title: Tire

paragraphs: A tire (British tyre) is a ring of material that covers the rim of a wheel. Most road vehicles and many other vehicles use rubber tires. Tires help vehicles to move smoothly. Some metro trains and trams also use rubber tires on their steel wheels to provide better traction than the steel tires of other trains.

paragraphs: Tires need to be changed after their treads wear away. Driving with worn tires is very dangerous. It can cause the tire to explode and the driver to lose control.

paragraphs: Tires were made of leather for thousands of years, and of iron or steel for hundreds. Pneumatic tires were invented in the 1840s and again in the 1880s. They became commonplace early in the 20th century.

paragraphs: Tires are made of different types of rubber. Softer rubber is used in summer or when the tires need better traction, for example, in auto racing. Tires made of harder rubber are made for long lasting performance, like long-distance truck carriers. There are many different types of tires. They come in different sizes and have different tread patterns.

paragraphs: There are many different sizes of tires. On car and truck tires, they are marked with 3 numbers and might look like: 225/60R16. The first number is the width in millimeters of the tire at the widest point when it is mounted and inflated. The second number is the sidewall (side of the tire) height as a ratio or percentage of the width. The last number is the wheel diameter in inches.

paragraphs: Very large tires (for example, tires on big mining trucks) use different units. For example: 59/80R63. The first number is the width in inches of the tire. The second number is the sidewall height as a ratio of the width. The last number is the wheel diameter in inches.

paragraphs: Most tires today do not have a tube inside of them. There are grooves in the wheel that let the tire be popped into place and hold a lot of air pressure. If there is a crack in the tire, it will not be able to hold its air. Tire leaks are very common. The most common cause is a hole from a nail or screw. This can usually be fixed by patching the inside of the tire so that it can hold air again. If the hole is close to or in the side of the tire, it can not be fixed. This is because the sides of the tire flexes to support the weight of the vehicle. A patch will not be able to handle the stress.

paragraphs: Mud and Snow, (or M+S, or M&S), is a designation used by manufacturers for all-season and winter tires. Most are designed to provide improved performance under low temperature conditions, compared to summer tires. The tread compound is usually softer than that used in tires for summer conditions. This provides better grip on ice and snow, but wears more quickly at higher temperatures. Tires may have well above average numbers of sipes in the tread pattern to grip the ice. M&S relates to the percentage of tread void area. On four-wheel drive vehicles, M&S tires are often standard equipment.


title: Population

paragraphs: A population is the number of living people that live together in the same place. A city's population is the number of people living in that city. These people are called inhabitants or residents. The population includes all individuals that live in that certain area.The world population was estimated to have reached 7.5 billion in April 2017. Asia is the most populous continent, with its 4.3 billion inhabitants being 60% of the world population. The most populous country is China with 1.4 billion people.

paragraphs: Population density is the average number of people in a place. Urban areas such as big cities have a high population density. People there live close to each other. In areas with a low population density, people usually live far away from each other, such as in rural areas out in the countryside.

paragraphs: Usually population refers to the number of humans in a certain area. The maximum population that can be supported in an area is called the carrying capacity.

paragraphs: Global population is going up, but the population growth rate is declining all over the world. Growth in poor countries is faster than in rich ones; some rich countries have a population pyramid that is nearly square. Urbanization is also common, and urban areas usually have lower birth rates. In population growth, births exceed deaths. In the modern world this is due to reduction of infant deaths, control of infectious diseases, and improved agriculture so more people can eat.

paragraphs: The change in population from 2010 to 2015 was:

paragraphs: Human population control is the practice of altering the rate of growth of a human population. Concerns about overpopulation and its effects on poverty, environmental degradation, and political stability led to efforts to reduce population growth rates.


title: Snow

paragraphs: Snow is a form of ice. Snow forms when water in the atmosphere becomes frozen. Snow comes in all different shapes and sizes.

paragraphs: At the freezing point of water (0° Celsius, 32° Fahrenheit), snow melts and becomes liquid water. Sometimes, the snow will melt very fast and become water vapor. This is called sublimation. The opposite, where water vapor becomes snow, is called deposition.

paragraphs: Snow is used for some winter sport activities like skiing and sledding. Sometimes people make artificial snow so they can ski. People also commonly build things out of snow for fun.

paragraphs: Snow can also be dangerous, as it can lower visibility and make driving very difficult. When it snows, the snow will melt a little during the daytime and freeze again at night. This makes ice which can make driving conditions very treacherous. Snow plows are used to remove snow from roads to make driving easier and safer. Also, sand or salt may be added to the road to help tires grip the road. When salt is mixed with snow, the snow will melt more easily. This is because salt water has a lower melting point than fresh water (water without salt).

paragraphs: A blizzard is a dangerous type of a snowstorm. A blizzard produces strong winds that keep the snow in the air, thus reducing visibility. Sometimes it produce thunder snow, which is snow with lightning and thunder.


title: West

paragraphs: West is one of the 4 main directions on a compass. West is normally to the left on most maps. For example: (Germany is located to the west of Poland, which is itself located to the west of Lithuania). When “The West” is used in everyday speech: it usually refers to the nations of Europe (Especially from Croatia Westward) and its daughter states in the Americas and Australasia. The sun and moon also set in the west.


title: President

paragraphs: A president is the leader of a country or a company or other group. A president is usually elected by the people in that group. Voting is one way to elect a president.

paragraphs: The President of the United States is elected by the electoral college. Some other countries choose a president this way. In some, the Parliament does it. Some countries have direct elections to choose a president. Many countries have a monarch instead of a president and some have neither.

paragraphs: Companies have presidents. They are elected by the people who own part of the company. In some companies, the people who are workers for the company elect (vote for) their company president.

paragraphs: The president of a country is not the same thing as a prime minister. A prime minister is part of a parliament, but a president is not. In some countries, (such as the United States or France), the president has more power and responsibility than anyone else. Such a president is often called the nation's chief executive. As chief executive, the president must take an active role in all phases of government. In other countries (such as India, Israel or the Republic of Ireland), to be president is more of an honor or a symbol, and the position has no real power. This kind of president is often called "head of state".

paragraphs: Most countries that have a King or Queen as their monarch have no president.

paragraphs: The American President is restricted by the written United States Constitution, which was written to make sure that the American executive never became as powerful as in the British system. The British Prime Minister is part of both the Legislature and Executive, whereas the American President is the head of the Executive. The American governmental system shows a clear separation of powers unlike the British system.

paragraphs: So despite having a large nuclear arsenal, the American president can not carry out policy and introduce legislation as freely as the British prime minister.


title: Galileo Galilei

paragraphs: Galileo Galilei (15 February 1564 – 8 January 1642) was an Italian polymath. Galileo was originally going to be a doctor but became a tutor instead. He was a professor of mathematics and natural science in Padua and Pisa. People most remembered him today for his conflict with the Catholic Church of his day, which led to his trial for heresy by the Inquisition.

paragraphs: Galileo was born on 15 February 1564 in Pisa, Duchy of Florence. He was the eldest of five siblings. His father was Vincenzo Galilei, who was a scholar and a musician. In 1574, the Galileo family moved to Florence and he started his formal education in the Camaldolese monastery.

paragraphs: Some people believe that Galileo was the first person to build a telescope. This is not true, but he was the first person to publish his observations of astronomical objects through a telescope. He discovered that the Milky Way is made of many stars. He discovered that the Moon has hills. He found four moons around Jupiter. Those moons are now called the Galilean moons. He discovered sunspots, which are dark areas of the Sun. He saw that the planet Venus has light and dark phases just like the Moon. This helped people to know that the Sun is at the centre of the Solar System, as Nicolaus Copernicus had said.

paragraphs: Galileo worked more at physics than at astronomy. He studied natural forces, and was one of the most important discoverers of the part of physics that is now called kinematics, including the discovery of the kinematic principle of relativity. However, he is often remembered now for things that either did not happen, or failed.

paragraphs: A legend says that he climbed the Leaning Tower of Pisa, and dropped cannonballs of different weights, to see which would strike the ground first. Even though their weights were not the same, they hit the ground at the same time. Galileo found that objects fall to the ground at the same rate, unless things like wind resistance change the rate. This went against the views of Aristotle, an ancient philosopher whose theory was different. Galileo's findings were ignored by most people, and Aristotle's view was still accepted as correct until Isaac Newton proved Galileo was right. This also led to Newton creating his Law of Gravity.

paragraphs: Galileo also tried to determine the speed of light. He climbed a hill, and had an assistant climb another hill, both carrying lanterns with closed shutters. He then opened the shutter of his lantern. His assistant opened his own shutter when he saw Galileo's lantern. Galileo then measured the time it took for his assistant's shutter to open. Knowing the time difference, and the distance between the hills, he tried to estimate the speed of light. However, this did not work.

paragraphs: Galileo came to accept the findings of Copernicus, that the Sun was the center of the then-known universe, and not the Earth. Because he promoted this and other ideas, he came to the notice of the Committee of Propaganda, the dreaded Inquisition. The Church taught that the Earth stood still, while everything in the sky moved around it. The Inquisition ruled in 1616 that other theories could only be discussed as possibilities, not facts. Galileo said he would obey. He played a major part in the scientific revolution through this argument.

paragraphs: Galileo later discussed the question in his most famous work, "Dialogue Concerning the Two Chief World Systems", published in 1632 by permission of the Inquisition. His scientific writing was usually in Latin for hundreds of scientists around Europe, but this was one of the books he wrote in Italian so thousands of Italians could read it. The book was in the form of conversations between three men. The man representing the Church's point of view was called 'Simplicio'.

paragraphs: Church leaders who liked his earlier books were angry at this one. The Inquisition took action in 1633. He was arrested and put on trial. They found him "vehemently suspect of heresy". They reminded him of the fate of Giordano Bruno, who had been burnt at the stake for heresy on topics such as transubstantiation and the Trinity. Bruno also believed the Earth went round the Sun and stars had planets. The Inquisition forced Galileo to recant (say he was wrong) under the threat of execution, and to withdraw his works from publication. Galileo spent the last ten years of his life under house arrest. Galileo continued to write about physics and other topics, but not astronomy.

paragraphs: Galileo has become synonymous with a warrior for scientific truth. Although he had to retract his writings at his trial,it is widely believed that after the trial he insisted that Earth does move around the sun, saying the famous phrase ""Eppur si muove"' – "still it moves." The saying itself became a slogan for science.

paragraphs: Galileo Galilei died on in Arcetri, Grand Duchy of Tuscany, Italy.

paragraphs: Previously, he was buried in a small room next to the novices' chapel at the end of a corridor. Later, he was reburied in the main body of the basilica in 1737 after a monument had been built there in his honour.


title: Agreement

paragraphs: When people feel or think the same way about something, they agree. Sometimes it is important to write down or make a promise to what has been agreed on. This is called an agreement. Agreements are common in law and business. For example, when a person takes out a loan or hires someone to work, an agreement is usually signed so everyone understands what must be done and in what time it must be done.


title: Promise

paragraphs: When a person agrees to do something or to "not" do something, that person is making a promise. A promise can be made (by saying it), or it can be written down as a contract. "Breaking" a promise, or not keeping it, is often just bad manners, but it can sometimes be illegal, such as when a contract is not kept.

paragraphs: A vow is a special promise. It is mostly used in a religious sense or in ceremonies such as marriages when the couple who are being married make their "marriage vows", promising to be faithful to one another.

paragraphs: An oath is a promise in the legal sense. When someone has to give evidence in a court of law they "swear an oath". This means that they promise they will tell the truth.


title: Cloud

paragraphs: A cloud is water vapour in the atmosphere (sky) that has condensed into very small water droplets or ice crystals that appear in visible shapes or formations above the ground.

paragraphs: Water on the Earth evaporates (turns into an invisible gas) and rises up into the sky. Higher up where the air is colder, the water condenses: it changes from a gas to drops of water or crystals of ice. We see these drops of water as clouds. The drops fall back down to earth as rain, and then the water evaporates again. This is called the "water cycle".

paragraphs: The atmosphere always has some water vapour. Clouds form when the atmosphere can no longer hold all the invisible air vapor. Any more water vapor condenses into very small water drops.

paragraphs: Warm air holds more water vapor than cool air. So if warm air with lots of water inside cools, it can form a cloud. These are ways air can cool enough to form clouds:

paragraphs: Clouds are heavy. The water in a cloud can have a mass of several million tons. Every cubic metre (m3) of the cloud has only about 5 grams of water in it. Cloud droplets are also about 1000 times heavier than evaporated water, so they are much heavier than air. They do not fall, but stay in the air, because there is warm air all round the heavier water droplets. When water changes from gas to droplets, this makes heat. Because the droplets are very small, they "stick" to the warm air.

paragraphs: Sometimes, clouds appear to be brilliant colors at sunrise or sunset. This is due to dust particles in the air.

paragraphs: Clouds are classified according to how they look and how high the base of the cloud is in the sky. This system was suggested in 1803. There are different sorts of clouds because the air where they form can be still or moving forward or up and down at different speeds. Very thick clouds with large enough water droplets can make rain or snow, and the biggest clouds can make thunder and lightning.

paragraphs: There are five basic families of clouds based on how they look:

paragraphs: The following is a summary of the main cloud types arranged by how high they form:

paragraphs: High clouds form from in cold places, in mild regions and in the very hot tropics. They are too high and thin to produce rain or snow.

paragraphs: Middle clouds usually form at in colder areas. However, they may form as high as in the tropics where it's very warm all year. Middle clouds are usually made of water droplets but may also have some ice crystals. They occasionally produce rain or snow that usually evaporates before reaching the ground.

paragraphs: Low-level clouds are usually seen from near ground level to as high as . Low clouds are usually made of water droplets and may occasionally produce very light rain, drizzle, or snow.

paragraphs: When very low stratus cloud touches the ground, it is called fog.

paragraphs: These are clouds of medium thickness that can form anywhere from near ground level to as high as . Medium-level cumulus does not have "alto" added to its name. The tops of these clouds are usually not much higher than . Vertical clouds often create rain and snow. They are made mostly of water droplets, but when they push up through cold higher levels they may also have ice crystals.

paragraphs: These clouds are very tall with tops usually higher than . They can create heavy rain and snow showers. Cumulonimbus, the biggest clouds of all, can also produce thunderstorms. These clouds are mostly made of water droplets, but the tops of very large cumulonimbus clouds are often made mostly of ice crystals.

paragraphs: In the Bible, clouds are often a sign of God's presence.


title: Water cycle

paragraphs: The water cycle (or hydrological cycle) is the cycle that water goes through on Earth.

paragraphs: Water is essential for life as we know it. It is present throughout the Solar System, and was part of the Earth from its formation. The source of the water was the same as the source of the Earth's rock : the cloud particles which condensed in the origin of the solar system.

paragraphs: This is the process that water starts and ends in the water cycle.

paragraphs: Human activities that change the water cycle include:


title: Water vapor

paragraphs: Water vapor is water that is in the form of a vapor, or gas. It is a part of the water cycle. When liquid water is heated to boiling point, 100 degrees Celsius (212 F), it turns into vapor. Water vapor can also be produced directly from ice; this is called sublimation. Steam is water vapor, but clouds are liquid water. The amount of water vapor in air is called humidity and it affects weather conditions. In the cold, breathing out causes the water vapor in the breath to freeze.

paragraphs: Water vapor weighs less than air, thus slightly reduces the lift produced by an aircraft wing.

paragraphs: Water vapour is transparent. The small droplets that look white like mist are actually liquid.

paragraphs: Water vapour is a big cause of the greenhouse effect.

paragraphs: Water vapor is invisible but when it condenses it makes visible water.


title: Solid

paragraphs: Solid is one of the three common states of matter. The molecules in solids are closely bound together, they can only vibrate. This means solids have a definite shape that only changes when a force is applied. This is different to liquids and gases which move randomly, a process called flow.

paragraphs: When a solid becomes a liquid, this is called melting. Liquids become solid by freezing. Some solids, like dry ice, can turn into gas without turning liquid first. This is called sublimation.

paragraphs: The forces between the atoms in a solid can take many forms. For example, a crystal of sodium chloride (common salt) is made up of ionic sodium and chlorine, which are held together by ionic bonds. In diamond or silicon, the atoms share electrons and make covalent bonds. In metals, electrons are shared in metallic bonding. Some solids, like most organic compounds, are held together with "van der Waals forces" coming from the polarization of the electronic charge cloud on each molecule. The dissimilarities between the types of solid come from the differences between their bonding.

paragraphs: Most metals are strong, dense, and good conductors of electricity and heat. The mass of the elements in the periodic table, those to the left of a diagonal line drawn from boron to polonium, are metals. Mixtures of two or more elements in which the big component is a metal are known as alloys.

paragraphs: People have been using metals for many purposes since prehistoric times.

paragraphs: The strength and relialbility of metals has led to their widespread use in making of buildings and other things, as well as in most vehicles, many tools, pipes, road signs and railroad tracks. Iron and aluminium are the two most commonly used metals. They are also the most common metals in the Earth's crust. Iron is most commonly used in the form of an alloy, steel, which has up to 2.1% carbon, making it much harder than pure iron.

paragraphs: Since metals are good conductors of electricity, they are valuable in electrical tools and for carrying an electric current over long distances with little energy loss. Because of this, electrical power grids rely on metal cables to get electricity. Home electrical systems, for example, are wired with copper for its good conducting uses. The high thermal conductivity of most metals also makes them useful for stovetop cooking utensils.

paragraphs: Minerals are natural solids formed through many geological processes under high pressures. To be thought as a true mineral, a substance must have a crystal structure with uniform physical things throughout. Minerals differ in composition from pure elements and simple salts to very complex silicates with thousands of known forms. In contrast, a rock sample is a random aggregate of minerals and/or mineraloids, and has no specific chemical composition. Most of the rocks of the Earth's crust have quartz (crystalline SiO), feldspar, mica, chlorite, kaolin, calcite, epidote, olivine, augite, hornblende, magnetite, hematite, limonite and a few other minerals. Some minerals, like quartz, mica or feldspar are common, while others have been found in only a few places in the world. The largest group of minerals by far is the silicates (most rocks are ≥95% silicates), which are made largely of silicon and oxygen, also with ions of aluminium, magnesium, iron, calcium and other metals.


title: Evaporation

paragraphs: Evaporation is when a liquid becomes a gas without forming bubbles inside the liquid volume. If bubbles are formed we are talking instead about "boiling".

paragraphs: For example, water left in a bowl will slowly disappear. The water evaporates into water vapor, the gas phase of water. The water vapor mixes with the air.

paragraphs: The opposite of evaporation is condensation.

paragraphs: When the molecules in a liquid are heated, they move faster. This makes them full of energy and so the particles collide with each other, and eventually they become so far apart that they become a gas.

paragraphs: During evaporation only the molecules near the liquid surface are changing from liquid to vapor. During boiling the molecules inside the volume of the liquid are also changing to vapor. For this reason during evaporation no bubbles are formed, instead they are formed during boiling.

paragraphs: Evaporation can happen at any temperature, while boiling happens only at a specified temperature called the "boiling point". Evaporation happens slowly, but boiling happens quickly.

paragraphs: Some liquids evaporate more quickly than others. There are many factors that affect the evaporation rate.

paragraphs: The rate of evaporation depends on the liquid's exposed surface area (faster when increased), the humidity of surroundings (slower when increased), the presence of wind (faster when increased) and the temperature (faster when increased).

paragraphs: Liquid with high boiling points (those that boil at very high temperatures) tend to evaporate more slowly than those with lower boiling temperatures.

paragraphs: Evaporation is a very essential part of the water cycle.


title: Contract

paragraphs: A contract is an agreement or promise that the law can enforce. The law will enforce some agreements but not others. For example, in most places, if a parent promises to take a child to get ice cream, the law will not enforce that promise as a legal contract.

paragraphs: The legal rules about which promises are enforced by the law can be different in different places (or jurisdictions), but a contract is usually enforced only if it is made by people or groups who want it to be enforced and who know what they are doing.

paragraphs: Sometimes, a contract is written down and signed by the people agreeing to it, but it does not always need to be. People usually sign a contract when something important or costly is being done. For example, when people take a job, they will sometimes sign a contract with their employers. The contract will show what the person must do as part of his job, how much they will be paid, and so on. The person and the employer will sign the contract, and it will become a legal promise.

paragraphs: If someone breaks a contract, another person might sue him or her. In a lawsuit about a contract, the court will look at the contract, listen to what the people who made the contract say about it, and then make a decision about what the contract means.


title: Face

paragraphs: The face is a part of the body at the front of the head.

paragraphs: It is the part of us that others interact with. On the face are organs of sight, smell, hearing. Especially in a four-legged animal, the face is the part which goes first into the world, and that is why the sense organs and the mouth are there.

paragraphs: In humans, the face includes the hair, forehead, eyebrow, eyelash, eyes, nose, ears, cheeks, mouth, lips, teeth, skin, and chin.


title: Kolkata

paragraphs: Kolkata (spelled Calcutta before 1 January 2001) is the capital city of the Indian state of West Bengal. It is the second largest city in India after Mumbai. It is on the east bank of the River Hooghly. When it is called Calcutta, it includes the suburbs. This makes it the third largest city of India. This also makes it the world's 8th largest metropolitan area as defined by the United Nations. Kolkata served as the capital of India during the British Raj until 1911. Kolkata was once the center of industry and education. However, it has witnessed political violence and economic problems since 1954. Since 2000, Kolkata has grown due to economic growth. Like other metropolitan cities in India, Kolkata struggles with poverty, pollution and traffic congestion.

paragraphs: The discovery of the nearby Chandraketugarh, an archaeological site has proved that people have lived there for over two millennia. The history of Kolkata begins when the English East India Company arrived in 1690. Job Charnock, an administrator with the Company is traditionally known as the founder of this city. However some academics say that Charnock is not the city's founder.

paragraphs: At that time Kolkata, ruled by the Nawab of Bengal Siraj-Ud-Daulah, had three villages. They were Kalikata, Govindapur and Sutanuti. The British in the late 17th century wanted to build a fort near Govindapur. This was to become more powerful than Dutch, the Portuguese, and the French. In 1702, the British completed the construction of old Fort William, which was used to station its troops and as a regional base. Calcutta was declared a Presidency City, and later became the headquarters of the Bengal Presidency. When regular fights with French forces started, in 1756 the British began to upgrade their fortifications. When this was protested, the Nawab of Bengal Siraj-Ud-Daulah attacked and captured Fort William. This led to the infamous Black Hole incident. A force of Company sepoys and British troops led by Robert Clive recaptured the city the next year. Calcutta became the capital of British India in 1772. However, the capital shifted to the hilly town of Shimla during the summer months every year, starting from the year 1864. Richard Wellesley, the Governor General between 1797–1805, helped in the growth of the city and its public architecture. This led to the description of Calcutta as "The City of Palaces". The city was a centre of the British East India Company's opium trade during the 18th and 19th century; locally produced opium was sold at auction in Kolkata, to be shipped to China.


title: Pencil

paragraphs: A pencil is a kind of writing equipment that is also used to draw, usually on paper. Most pencil cores are made of graphite powder mixed with a clay binder. So, a pencil is usually made with a piece of graphite mixed with clay that has a wood case around it. The shape is usually a hexagonal prism but some pencils are square or cylinder.

paragraphs: Colored pencils are a kind that do not use greyish silver graphite. Instead, the core is colorful. Colored pencils or crayons are usually meant for drawing rather than writing.

paragraphs: The important difference between pens and pencils is that the tip of a pencil is made of solid graphite (or other material) which is rubbed off onto the paper. A pen has a tip, usually made of metal, with liquid ink coming out and onto the paper. Writing with a pen can smudge when it is still wet. Writing from a pencil can be erased, but writing from a pen usually cannot, unless it uses a special type of ink and eraser.

paragraphs: An early writing tool was the reed pen used by ancient Egyptians, who wrote with ink on sheets of papyrus paper.

paragraphs: Another early writing instrument was the stylus, which was a thin metal stick, often made from lead. It was used for scratching onto black wax that covered white wood, a method used by the Romans. The word "pencil" comes from the Latin word which means "little tail". It is an invention of the 16th century in England.

paragraphs: Some time before 1565 (it may have been as early as 1500), an enormous deposit of graphite was discovered in Borrowdale, Cumbria. The locals found that it was very useful for marking sheep. This particular deposit of graphite was extremely pure and solid, and it could easily be sawn into sticks. This is still the only large scale deposit of graphite ever found in this solid form. Chemistry was in its infancy and the substance was thought to be a form of lead. Consequently, it was called "plumbago" (Latin for "lead ore"). The black core of pencils is still referred to as "lead", even though it never contained the element lead.

paragraphs: The value of graphite was soon realized, mainly because it could be used to line the moulds for cannonballs. The mines were taken over by the Crown and guarded. When sufficient stocks of graphite had been accumulated, the mines were flooded to prevent theft until more was required. Graphite had to be smuggled out for use in pencils. Because graphite is soft, it requires some form of holder. Graphite sticks were at first wrapped in string or in sheepskin for stability. The news of the usefulness of these early pencils spread far and wide, attracting the attention of artists all over the known world.

paragraphs: England continued to have a monopoly on the production of pencils until a method of reconstituting the graphite powder was found. The distinctively square English pencils continued to be made with sticks cut from natural graphite into the 1860s. The town of Keswick, near the original findings of block graphite, has a pencil museum.

paragraphs: The first attempt to manufacture graphite sticks from powdered graphite was in Nuremberg, Germany, in 1662. It used a mixture of graphite, sulphur, and antimony.

paragraphs: Residual graphite from a pencil stick is not poisonous, and graphite is harmless if consumed.

paragraphs: The Italians first thought of wooden holders. In 1560, an Italian couple named Simonio and Lyndiana Bernacotti created the first blueprints for the modern carpentry pencil to mark their carpentry pieces. Their version was instead a flat, oval, more compact type of pencil. They did this at first by hollowing out a stick of juniper wood. Shortly thereafter, a superior technique was discovered: two wooden halves were carved, a graphite stick inserted, and the two halves then glued together–essentially the same method in use to this day.

paragraphs: English and German pencils were not available to the French during the Napoleonic Wars. France was under naval blockade imposed by Great Britain and could not import the pure graphite sticks from the British Grey Knotts mines – the only known source in the world for solid graphite. France was also unable to import the inferior German graphite pencil substitute. It took the efforts of an officer in Napoleon's army to change this. In 1795, Nicholas Jacques Conté discovered a method of mixing powdered graphite with clay and forming the mixture into rods that were then fired in a kiln. By varying the ratio of graphite to clay, the hardness of the graphite rod could also be varied. This method of manufacture, which had been earlier discovered by the Austrian Joseph Hardtmuth of Koh-I-Noor in 1790, remains in use.

paragraphs: In England, pencils continued to be made from whole sawn graphite. Henry Bessemer's first successful invention (1838) was a method of compressing graphite powder into solid graphite thus allowing the waste from sawing to be reused.

paragraphs: American colonists imported pencils from Europe until after the American Revolution. Benjamin Franklin advertised pencils for sale in his "Pennsylvania Gazette" in 1729, and George Washington used a three-inch pencil when he surveyed the Ohio Territory in 1762. It is said that William Munroe, a cabinetmaker in Concord, Massachusetts, made the first American wood pencils in 1812. This was not the only pencil-making occurring in Concord. According to Henry Petroski, transcendentalist philosopher Henry David Thoreau discovered how to make a good pencil out of inferior graphite using clay as the binder; this invention was prompted by his father's pencil factory in Concord, which employed graphite found in New Hampshire in 1821 by Charles Dunbar.

paragraphs: On 30 March 1858, Hymen Lipman received the first patent for attaching an eraser to the end of a pencil. In 1862 Lipman sold his patent to Joseph Reckendorfer for $100,000, who went to sue the pencil manufacturer Faber-Castell for infringement. In 1875, the Supreme Court of the United States ruled against Reckendorfer declaring the patent invalid.

paragraphs: The metal band used to mate the eraser with pencil is called a ferrule.

paragraphs: The first attempt to manufacture graphite sticks from powdered graphite was in Nuremberg, Germany in 1662. They used a mixture of graphite, sulfur and antimony. Though usable, they were not as good as the English pencils.

paragraphs: English and German pencils were not available to the French during the Napoleonic wars. It took the efforts of an officer in Napoleon's army to change this. In 1795 Nicholas Jacques Conté discovered a method of mixing powdered graphite with clay and forming the mixture into rods which were then fired in a kiln. By varying the ratio of graphite to clay, the hardness of the graphite rod could also be varied (the more clay, the harder the pencil, and the lighter the color of the mark). This method of making pencils is still used today.

paragraphs: Today, pencils are made industrially by mixing finely ground graphite and clay powders, adding water, forming long spaghetti-like strings, and firing them in a kiln. The resulting strings are dipped in oil or molten wax which seeps into the tiny holes of the material, resulting in smoother writing. A juniper or incense-cedar plank with several long parallel grooves is cut to make something called a slate, and the graphite/clay strings are inserted into the grooves. Another grooved plank is glued on top, and the whole thing is then cut into individual pencils, which are then varnished or painted.

paragraphs: A few common brands of colored pencils (among other items) are Crayola, RoseArt and Cra-Z-Art.


title: Logic

paragraphs: Logic is the study of reasoning. The rules of logic let philosophers make valid logical deductions about the world. Logic helps people decide whether something is true or false.

paragraphs: Logic is often written in syllogisms, which are one type of logical proof. A syllogism is made from a collection of statements used to logically prove the final statement, called the conclusion. One popular example of a logical syllogism was written by the Classical Greek philosopher Aristotle:

paragraphs: The conclusion is the final statement. This syllogism connects the first two statements to make a logical deduction: Socrates is mortal.

paragraphs: The syllogism is made from three logical statements or propositions. These statements are short sentences describing a small step in a logical argument. The small statements make up the argument, the same way atoms make up molecules. When logic is correct, the statements are said to "follow" from each other.

paragraphs: Statements have a truth value, meaning they can be proved to be true "or" false, but not both. Illogical statements or mistakes in logic are called logical fallacies.

paragraphs: Logical statements can be written in a special type of short hand writing, which includes the symbols of the symbolic logic. These symbols are used to describe logical reasoning in an abstract way. For example:

paragraphs: Here is the previous syllogism written in symbolic logic.

paragraphs: By replacing the English words with letters, one can make the syllogism even simpler.

paragraphs: Similar to mathematical symbols for operations like addition and subtraction, symbolic logic separates abstract logic from the English-language meaning of the original statements. With these abstract symbols, people can study pure logic without the use of a specific written language.

paragraphs: The syllogism is now written in the most abstract and simple way possible. Any distracting elements, such as English language words, have been removed. Anyone who understands logical symbolism can understand this argument.

paragraphs: A logical proof is a list of statements put in a specific order to prove a logical point. Each statement in the proof is either an assumption made for the sake of argument, or has been proven to follow from earlier statements in the proof. All proofs must start with some assumptions, such as "humans exist" in the above syllogism. A proof shows that one statement, the conclusion, follows from the starting assumptions. With a proof, we can prove that "Aristotle is mortal" logically follows from "Aristotle is a man" and "All men are mortal".

paragraphs: Some statements are always true. That kind of statement is called tautology"." One popular classical tautology, credited to the philosopher Parmenides of Elea, says "That which is, is. That which is not, is not." This essentially means that true statements are true and false statements are false. Due to their simple nature, tautologies may not always be helpful in building logical arguments.

paragraphs: A tautology is represented in symbolic logic as formula_9, meaning "Either "a" or not "a"." Assuming that there are no unmentioned possibilities, this covers every possible case. Another symbol used to represent a tautology is formula_10.

paragraphs: Because logic is a tool used to think more rationally, it can be used in countless ways. Symbolic logic is employed far and wide, from philosophical treatises to complicated mathematical equations. Computers use the rules of logic to run algorithms, which let computer programs make decisions based on data.

paragraphs: Logic is critical to pure mathematics, statistics, and data analysis. Logic is also studied in philosophy. People who study math create proofs that use logical rules to show that mathematical theorems are correct. There is an area of mathematics called mathematical logic that studies logic using mathematics.


title: Communism

paragraphs: Communism is a socio-economic political movement. Its aim is to set up a version of society based on the common ownership of the means of production and would not rely on social classes, or money.

paragraphs: According to communist writers and thinkers, the goal of communism is to create a stateless, classless society and to end capitalism. Communist thinkers believe this can happen if the people take away the power of the bourgeoisie (the ruling class, who own the means of production) and establish worker control of the means of production.

paragraphs: Communism is not anti-individualist. However, it does say that decisions should be good for the population as a whole, instead of just being good for only some part of people in the country.

paragraphs: Since 1992, there have been five nations remaining governed officially by communist ideologies. Four of these follow different forms of Marxism-Leninism - Vietnam, China, Cuba and Laos. The fifth, North Korea, now officially follows Juche communism, but also called itself Marxist-Leninist before 1991. Many other nations abandoned Marxism around that time because most people thought it had failed. In many cases it caused a corruption of ideals and led to authoritarianism, mass poverty, economic collapse and violent conflict, as is the case of the Soviet Union and Yugoslavia, for example.

paragraphs: Some of the most notable individuals have been instrumental in the development of communism include: Karl Marx, Friedrich Engels, Joseph Stalin, Vladimir Lenin, and Leon Trotsky.

paragraphs: In 1848, Karl H. Marx and Friedrich Engels wrote "The Communist Manifesto". It was a short book with the basic ideas of communism. Most socialists and communists today still use this book to help them understand politics and economics. Many non-communists read it too, even if they do not agree with everything in it.

paragraphs: Karl Marx said that for society to change into a communist way of living, there would have to be a period of change. During this period, the workers would govern society. Marx was very interested in the experience of the Paris Commune of 1870, when the workers of Paris ran the city following the defeat of the French Army by the Prussian Army. He thought that this practical experience was more important than the theoretical views of the various radical groups.

paragraphs: Many groups and individuals liked Marx's ideas. By the beginning of the twentieth century, there was a worldwide socialist movement called Social Democracy. It was influenced by his ideas. They said that the workers in different countries had more in common with each other than the workers had in common with the bosses within their own countries. In 1917, Vladimir Lenin and Leon Trotsky led a Russian group called the Bolsheviks in the October Revolution. They got rid of the temporary government of Russia, which was formed after the February Revolution against the Tsar (Emperor). They established the Union of Soviet Socialist Republics, also called the Soviet Union or USSR.

paragraphs: The Soviet Union was the first country claiming to have established a workers' state. In reality, the country never became communist in the way that Marx and Engels described.

paragraphs: During the 20th century, many people tried to establish workers' states. In the late 1940s, China also had a revolution and created a new government with Mao Zedong as its leader. In the 1950s, the island of Cuba had a revolution and created a new government with Fidel Castro as its leader. At one time, there were many such countries, and it seemed as though communism would win. But communist party governments didn't use democracy in their governments, a very important part of socialism and communism. Because of this, the governments became separated from the people, making communism difficult. This also led to disagreements and splits between countries.

paragraphs: By the 1960s, one-third of the world had overthrown capitalism and were trying to build communism. Most of these countries followed the model of the Soviet Union. Some followed the model of China. The other two-thirds of the world still lived in capitalism, and this led to a worldwide divide between capitalist countries and communist countries. This was called the "Cold War" because it was not fought with weapons or armies, but competing ideas. However, this could have turned into a large war. During the 1980s, the United States and the Soviet Union were competing to have the biggest army and having the most dangerous weapons. This was called the "Arms Race". President Ronald Reagan called communist countries like the Soviet Union the "Evil Empire" because he did not agree with communist ideas.

paragraphs: Since 1989, when the Berlin Wall was torn down, most countries that used to be communist have returned to capitalism. Communism now has much less influence around the world. In 1991, the Soviet Union broke up. However, around a fifth of the world's people still live in states controlled by a communist party. Most of these people are in China. The other countries include Cuba, Vietnam, Laos, and North Korea. There are also communist movements in Latin America and South Africa.

paragraphs: Many people have written their own ideas about communism. Vladimir Lenin of Russia thought that there had to be a group of hard-working revolutionaries (called a vanguard) to lead a socialist revolution worldwide and create a communist society everywhere. Leon Trotsky, also from Russia, argued that socialism had to be international, and it was not important to make it happen first in Russia. He also did not like Joseph Stalin, who became the leader of the USSR after Lenin's death in 1924. Trotsky was made to leave the Soviet Union by Stalin in 1928, and then killed in 1940. This scared many people, and lots of communists argued about whether this was right and whose ideas should be followed.

paragraphs: Mao Zedong of China thought that other classes would be important to the revolution in China and other developing countries because the working classes in these countries were small. Mao's ideas on communism are usually called Maoism or Mao Zedong Thought. After Stalin's death in 1953, Mao saw himself as the leader of worldwide communism until he died in 1976. Today the Chinese government is still ruled by the Communist Party, but they actually have what is called a mixed economy. They have borrowed many things from capitalism. The government in China today does not follow Maoism. However, few revolutionaries in other countries like India and Nepal still like his ideas and are trying to use them against in their own countries.

paragraphs: The word "communism" is not a very specific description of left-wing political organizations. Many political parties calling themselves "communist" may actually be more reformist (supportive of reforms and slow change instead of revolution) than some parties calling themselves "socialists". Many communist parties in Latin America have lost many members because these parties do different things than what they promised once they get into power. In Chile, between 1970-1973, under the left-wing Coalition (groups of parties) of Popular Unity, led by Salvador Allende, the Communist Party of Chile was to the right of the Socialist Party of Chile. This means it was more reformist than the socialist party.

paragraphs: Many communist parties will use a reformist strategy. They say working-class people are not organized enough to make big changes to their societies. They put forward candidates that will be elected democratically. Once communists become elected to parliament or the Senate, then they will fight for the working class. This will allow working-class people to change their capitalist society into a socialist one.

paragraphs: The color red is a symbol of communism around the world. A red five-pointed star sometimes also stands for communism. The hammer and sickle is a well-known symbol of communism. It was on the flags of many communist countries (see top of article). Some communists also like to use pictures of famous communists from history, such as Marx, Lenin, and Mao Zedong, as symbols of the whole philosophy of communism.

paragraphs: A song called "The Internationale" was the international song of communism. It has the same music everywhere, but the words to the song are translated into many languages. The Russian version was the national anthem of the Soviet Union from 1922 until 1944.

paragraphs: The sickle in the Soviet Union's flag shows the struggle of the pesants-farmers. The hammer in the flag represents the struggle for the workers. Both of them crossing shows their support for each other.

paragraphs: There is also a special kind of art and architecture found in many communist and former communist countries. Paintings done in the style of socialist realism are often done for propaganda to show a perfect version of a country's people and political leader. Art done in the socialist realism style, such as plays, movies, novels, and paintings show hard-working, happy, and well-fed factory workers and farmers. Movies, plays and novels in this style often tell stories about workers or soldiers who sacrifice themselves for the good of their country. Paintings often showed heroic portraits of the leader, or landscapes showing huge fields of wheat. Stalinist architecture was supposed to represent the power and glory of the state and its political leader. Some non-communists also enjoy this kind of art.


title: Resurrection

paragraphs: Resurrection means bringing someone back to life after they have died.

paragraphs: The idea of resurrection is found in writings of ancient polytheistic religions in the Middle East. Some Egyptian and Canaanite writings tell of gods being resurrected, such as Osiris and Baal.

paragraphs: In Greek mythology, many men and women were given eternal life by being resurrected from the dead. In their stories, some who came back to life as gods were Alcmene, Castor, Heracles, and Melicertes. But the Greek philosophers at that time did not believe in a physical rebirth.

paragraphs: Christians believe that Jesus Christ was resurrected. They also believe in resurrection for all people after they die. This is based on the Gospels and on Saint Paul's writings in the New Testament. The resurrection of Jesus is the Christian belief that he returned to life by a miracle. He died by crucifixion on Friday and rose from his tomb to new life on Sunday morning. This belief is celebrated at Easter.

paragraphs: The resurrection of Jesus Christ is written about by the evangelists in the New Testament. They are the authors of the four Gospels in the New Testament. Christians believe the resurrection is a central part of the Christian faith. Jesus died on the cross to save mankind. When he was resurrected, Jesus defeated death. He is alive forever and sitting at God's right hand on a throne. This gives Christians the hope of a new life after death. This is because his resurrection mirrors the future for all Christians after they die.

paragraphs: With Jesus Christ and with humans, the Bible shows that the resurrected body is changed from the original. This is because the human body, while alive, is weak and frail. But, the resurrected person lives for ever.

paragraphs: All four Gospels tell about Jesus being raised from the dead. They also write about three times that Jesus brings a dead person back to life:

paragraphs: In Islam, the Quran refers to a bodily resurrection of all those who have died.

paragraphs: This will be followed by a final time of trouble and eternal division of the righteous and wicked. Islamic apocalyptic literature describing Armageddon is often known as The Great Massacre or "ghaybah" in Shī'a Islam. The righteous are rewarded with the pleasures of Jannah (Paradise), while the unrighteous are punished in Hell.

paragraphs: According to Alcor, resurrection of a legally dead people will be possible in the far future. They are using Cryonics to preserve some legally dead people until the invention of the resurrection.


title: Monarchy

paragraphs: A monarchy is a kind of government where a monarch, a kind of hereditary ruler (someone who inherits their office), is the head of state. Monarchs usually rule until they die or pass down (when a monarch resigns it is called abdication). Most monarchies are hereditary, but some are elected. The most famous elected monarch is the Pope of the Roman Catholic Church. Some well known titles for monarchs are King, Queen, Emperor, Empress, Czar, Kaiser, Shah, Emir and Sultan.

paragraphs: Monarchy is one of the oldest kinds of government. Most historians agree that the first monarchies were tribes or small groups of people who decided to let a war-chief or other leader pass on their office to their children. This created a dynasty. Over time, the rules for deciding who got to become the next monarch became more complicated. Primogeniture is usual. The oldest son or, in some countries, daughter, becomes the next monarch when the old one dies.

paragraphs: Kings and other kinds of monarchs have ruled for many thousands of years; for example, many kings are mentioned in the Bible and in ancient historical records. Three of the oldest countries with monarchs that still hold office are the United Kingdom, which has had the same British Royal Family for nearly 1,000 years, Denmark where the royal line has remained unbroken for almost 1,200 years, and Japan, which has records showing a line of Emperors dating back even farther.

paragraphs: Many monarchs today perform mostly the ceremonial jobs of a head of state, while the head of government, who is usually elected, passes and enforces laws. It is also very important in other parts of the country.

paragraphs: In an absolute monarchy the monarch is the only source of all laws. The monarch has total power to make any law just by deciding it. Any other institution in the country cannot make laws that affect the monarch, unless the monarch decides to allow it. Sometimes the monarch is also the head of the state religion and makes religious laws also. All land and property in the country can be taken or given away by the monarch at any time for any reason. The army and navy is under the personal control of the monarch and can be used for any purpose at any time. The monarch can also pick who gets to be the next monarch and can change the rules at any time. There is usually no elected government or Parliament, and if there is one, it has no real power. This kind of government is very rare today. The people do not have a lot of power in it.

paragraphs: Countries that are examples of an absolute monarchy are Vatican City, Brunei, Qatar, Saudi Arabia, Oman and Swaziland.

paragraphs: A constitutional monarchy is a form of government that is usually a democracy and has a constitution, with the monarch as head of state. Either the monarch has to obey the laws like everyone else, or there are special laws that say what the monarch can and cannot do. The monarch usually can not decide their special laws on their own. There may be laws about whom the monarch's children can marry, for example, that are passed by the Parliament. For example, in the Netherlands, if a member of the royal family marries without the permission of Parliament, they cannot become king or queen themselves. The army and navy may swear an oath to the monarch, but the real control is given to the elected government. There are laws about property and the order of succession (who gets to be the next monarch) that can only be changed by the elected government. Usually the monarch must sign laws into effect, but is required to follow the will of the elected government.

paragraphs: A constitutional monarchy usually has separation of powers, and the monarch often has only ceremonial functions, such as representing the country while traveling or acting as a symbol for the whole country (not for a particular political party). Constitutional monarchs usually do not vote, even when it is legal for them to do so. Voting would mean that they picked a side in political arguments and then could not claim to represent everyone in the country. Some constitutional monarchies give the power to veto laws to the monarch, but in most countries where this is the case it is a power that is very rarely used. In countries where the monarch can dismiss or appoint governments, this is usually only done to make sure that the democratic process is respected, without taking sides in politics. Appointments to public office made by constitutional monarchs are generally approved by the democratically elected government beforehand.

paragraphs: Examples of Constitutional monarchies are the United Kingdom, most members of the Commonwealth of Nations, Australia, The Netherlands, Norway, Denmark, Sweden, Belgium, Japan and Spain. Thailand has a monarch who sometimes take part in politics to influence the government unlike in other constitutional monarchies, but he/she still is subject to law.

paragraphs: Today, there are three basic forms how to choose a new monarch, after the death of the old one; or because the old monarch left power:

paragraphs: Of these three, the order of succession is the most common case. Countries, where the monarchs are elected include Malaysia, Samoa, Cambodia, United Arab Emirates, Andorra, and Vatican City.


title: North Korea

paragraphs: North Korea (officially called the Democratic People's Republic of Korea (DPRK)), is a country in the northern part of the Korean peninsula. North Korea is next to China, Russia, and South Korea. The capital city of North Korea is Pyŏngyang, which is also the largest city.

paragraphs: The country was founded in 1948 after it had been freed from Japanese occupation, and a socialist state backed by the Soviet Union was established. The Republic of Korea is the southern half of the Korean Peninsula, and was occupied by the United States, and the U.S. set up a democracy in the south. At first there was a war between the armies of the North and South in what is called the Korean War, but while the fighting stopped in 1953, the war never officially ended. Afterwards, North Korea was friendly with China and Russia but never was formally allied with either and became more isolated over time. While the South had an unstable government after independence, the North went through steady development and was more well off than South until the 1980s when the South became more democratic. Soon afterwards, the North's main trading partners collapsed leaving it stranded and isolated. Throughout the 1990s, North Korea suffered from famines and natural disasters. Afterwards, things stabilized but continued to lag behind the South.

paragraphs: North Korea is generally viewed as a Totalitarian Stalinist dictatorship. The country's leader Kim Il-sung said that the government was following his own ideology of "Juche", which means "self-reliance". Later on, the country's leaders began to remove "communism" from North Korean laws and philosophy. After Kim Il-sung died during the disasters of the 1990s, his son Kim Jong-il took his place and was promoted by the government as the leader who led North Korea out of the disasters. Kim Jong-il enacted a new policy of "Songun", or "military-first", which turned the country into a military state. When he died in 2011, his youngest son Kim Jong-un took his place and continues to lead the country today.

paragraphs: Historians think that the Korean people have lived in the area for thousands of years. Before 1910, Korea was one country. It had a king and people were mostly farmers. The country was peaceful and was not communist. In 1910, that changed. Japan and Russia went to war. Since Japan and Russia were both very close to Korea, Japan took Korea for themselves as part of Japan. Japan then had control.

paragraphs: Between 1910 and the end of World War II in 1945, Korea was considered a part of Japan due to Japan's unethical colonization of Korea. In 1945, the USSR declared war on Japan and the United States bombed it (Nagasaki and Hiroshima); severely weakening its empire and forcing it to surrender. Japan's weak status allowed the Soviets to enter Korea fairly freely and occupy the northern half whilst the United States took the southern half. Each then created governments supporting their own ideologies, Marxist–Leninist Single Party State (North) and Democratic Capitalist State (South).

paragraphs: In 1950, North Korea sent soldiers to South Korea. North Korea wanted to bring together North and South Korea to form a single Korean country, and Korean families that had been split by the division of North and South to be together again. The North Korean leaders wanted South Korea to be communist, like North Korea and the Soviet Union were.

paragraphs: The United Nations sent soldiers to Korea. These soldiers came from many countries. These countries did not like Communism (to learn more, see the article about the Cold War). If South Korea became Communist, then maybe other countries would too. General Douglas MacArthur led the soldiers.

paragraphs: North Korea had taken over much of South Korea by force. With the help of the other countries, South Korea took back their land, and even much of North Korea, up to the Yalu River, which forms the border between North Korea and China. China, which was also communist, helped the North Koreans to get the land back that the South Korean soldiers had taken.

paragraphs: After three years, in 1953, North Korea and South Korea both decided that no one would win the war and both countries signed an armistice, which is an agreement that made both countries stop fighting. North Korea and South Korea were divided by a demilitarized zone, or DMZ, which is a special place that surrounds the border between North and South Korea where both countries can not place lots of soldiers, so that fighting does not start again.

paragraphs: Even though the Demilitarized Zone is meant to stop problems between the two countries, sometimes soldiers on both sides of the border fire their guns at each other. A special town in the zone, Panmunjom, is called the Joint Security Area, or JSA, and sometimes the leaders of both countries meet there to talk about possibly coming back together.

paragraphs: North Korea is one of the few countries in the world that has made nuclear missiles, which can kill many people if they are exploded. North Korea will not say how many nukes it has, but other countries think that the North Korean government probably has built ten missiles so far out of a deadly element called plutonium.

paragraphs: In October 2006, North Korea said that it tested one of its nuclear bombs. Although the North Korean government said that the test was not dangerous, many other countries and the United Nations were nonetheless enraged.

paragraphs: Three years later in 2009, North Korea did another test, which broke a United Nations law called Resolution 1718, which said North Korea could not keep building and testing nuclear bombs.

paragraphs: In 2010, a South Korean warship sank, killing over 40 soldiers. An international investigation concluded that North Korea had sunk a South Korean warship with a torpedo. North Korea strongly said that it did not have anything to do with the sinking. When the United States and South Korea planned to set up defenses in case North Korea tried to attack again, North Korea's National Defense Commission threatened on to start a war with its nuclear weapons.

paragraphs: In April 2012, North Korea launched a rocket called Bright Star 3. The reasons for the launch were science and the 100th anniversary of the birth of the country's founder, Kim Il-Sung.

paragraphs: The government said the rocket carried a weather satellite so the government could find out what the weather would be. However, other countries said that the weather satellite was a story made up by the government so the real purpose of the rocket would not the known—which most countries thought was to test a nuclear missile that could be launched at the United States or South Korea. South Korean leaders said it would shoot the rocket down when it came over South Korea.

paragraphs: Because of this rocket, other countries stopped helping North Korea, even though the government invited other countries to see the rocket launch to make it seem like the North Koreans had nothing to hide from other countries. The rocket was eventually launched, but it did not work and crashed just a minute and thirty seconds after it was launched. In December 2012, the government tried to launch the rocket again. It worked this time and went into orbit circling the Earth, though the United States said that it was very unstable and might fall back to Earth. Experts in Europe noticed the satellite's reflection was fluctuating (getting brighter then dimmer); indicating that the satellite is tumbling in its orbit.

paragraphs: In February 2013, North Korea tested a nuclear bomb for the 3rd time, causing much outrage from other countries. The government also released many videos that depicted possible missile targets in the United States. North Korea however does not posses missiles that could reach US mainland but some say Hawaii is a possibility. It is highly unlikely that North Korea would ever fire against the US, Japan or South Korea. Many missiles depicted in DPRK parades are fakes used to exaggerate North Korea's military strength. Most of its inventory dates from the Soviet years.

paragraphs: People often think that North Korea is a communist country. It is actually a socialist-military dictatorship. In its most recent constitutional change, the word 'communism' was removed. Large pictures of Karl Marx and Vladimir Lenin were removed from Kim Il-Sung square in 2012. The government has a similar structure to the former Soviet Union (USSR), once a close ally, but it is very different from the USSR. Leaders of the USSR were elected by a group of government officials. In North Korea, the new leader is the current leader's male heir. For this reason, North Korea is often referred to as a hereditary dictatorship.

paragraphs: North Korea's official state ideology is Juche. That is a form of socialism developed by the country's founder, Kim Il-Sung. Juche means self-reliance. It teaches that to achieve true socialism and become self-sufficient, the state must become fully isolated from the rest of society.

paragraphs: The first head of state and Chairman of the Workers Party of North Korea was Kim Tu-bong.

paragraphs: In the late 1950s, the second head of state and party chairman was Kim Il-Sung.

paragraphs: In July 1994, Kim died. His son, Kim Jŏng-Il, took over. He became the third head of state and party chairman.

paragraphs: In December 2011, Kim died. His son, Kim Jŏng-Un became the head of the government.

paragraphs: "Songun" is a North Korean idea. It means "army first." The job of every North Korean person is to feed the Army. Kim Jŏng-Un is the "Chairman of the National Defense Commission of North Korea". That is one of many jobs he has. He is like a king, and can do what he wants. The average North Korean citizen makes around $900 a year. Kim Jŏng-Un makes around $800,000 a year. He lives in a palace. He has lots of soldiers who go wherever he goes to protect him.

paragraphs: North Korea is technically a multi-party state since other parties do exist besides the Korean Workers' Party (KWP). However, the KWP also controls the other parties so it can stay in power. The constitution claims that North Korea's citizens have freedom of speech, religion and press. In real life, these citizens do not have these rights. People can be jailed if they criticise the party, government, or leaders. North Koreans are encouraged to report family members to the police if they think they are doing something illegal. In return they get more privileges. If someone is caught doing a crime, their whole family will be sent along with them to a labour camp. Most die there, but a few escape.

paragraphs: North Korean people have very little freedom of speech. They get their news from the Korean Central News Agency (KCNA). The KCNA makes sure all the country's television, radio, and newspaper news makes the government look good. This is called propaganda. The government blocks access to the Internet. Only a few trusted military officials and party members can access the world Internet. It has been reported that almost all North Koreans do not know that men have landed on the moon. The government runs an intranet service that is available on all North Korean computers. It is nothing like the real Internet but is filled with propaganda that makes the government, party, and leaders look good. The government also tries to keep ideas from other countries out of North Korea.

paragraphs: Capital punishment is a common type of punishment in North Korea. Stealing, murder, rape, drug smuggling, attempted murder, spying, trying to challenge the laws of North Korea, looking at media unapproved by North Korea, and religions that are against believing in Kim Jong-un and his family can result in the death penalty.

paragraphs: In parts of the country, there is not enough food. Currently, other countries give food to some people in North Korea. This is called "foreign aid". The aid sometimes stops coming if North Korea is thought to be testing nuclear bombs. Very recently, North Korea's food aid stopped after the government launched a satellite in April 2012. Other countries said North Korea had broken their side of an agreement. The North Korean government said that it was the United States that had broken the agreement.

paragraphs: It is hard for people from other countries to visit North Korea. Visitors must be guided by two army members called "minders". The minders try and make sure the people do not find out about anything that might make the government look bad.

paragraphs: Historically, both South Korea and North Korea have the same set of values. In 1945, the peninsula was divided. Since then, the government of both North and South Korea were different. This has led to different developments in both North and South Korea.

paragraphs: Human Rights Watch says that free religious activities do not exist in North Korea. The culture in Korea has been influenced by that of China. Despite this, Korea has developed a cultural identity that is different from that of Mainland China.

paragraphs: Literature and arts in North Korea are state-controlled. Specialized committees of the KWP are responsible for this. Film is also a significant artistic medium in North Korea and Kim Jong Il's manifesto "The Cinema and Directing" (1987) is the basis for the nation's filmmakers.

paragraphs: Korean culture came under attack during the Japanese rule from 1910 to 1945. Japan enforced a cultural assimilation policy. During the Japanese rule, Koreans were encouraged to learn and speak Japanese, adopt the Japanese family name system and Shinto religion, and were forbidden to write or speak the Korean language in schools, businesses, or public places. In addition, the Japanese altered or destroyed various Korean monuments including Gyeongbok Palace and documents which portrayed the Japanese in a negative light were revised.

paragraphs: Both Koreas share a Buddhist and Confucian heritage and a recent history of Christian and Cheondoism ("religion of the Heavenly Way") movements. The North Korean constitution states that freedom of religion is permitted. According to the Western standards of religion, the majority of the North Korean population could be characterized as non-religious. However, the cultural influence of such traditional religions as Buddhism and Confucianism still have an effect on North Korean spiritual life.

paragraphs: It seems that Buddhists are accepted more than other religious groups. Christians are said to be severely persecuted by the authorities. Buddhists are given limited funding by the government to promote the religion, because Buddhism played an integral role in traditional Korean culture. In May 2014, an American tourist was arrested at Pyongyang Sunan Airport after it was discovered he left a Bible in a nightclub on the DPRK's east coast. He was convicted of attempting to overthrow the government but was eventually released several months later. At the time of his imprisonment, there were two other American citizens held by North Korea awaiting transfer to political prison camps. Both have since been released.

paragraphs: The land of North Korea is divided into nine areas called provinces and two cities.


title: Parliament

paragraphs: The most famous parliament is probably the Parliament of the United Kingdom, which is sometimes called the "Mother of all Parliaments". The word "parliament" comes from the French word "parler", which means a talk.

paragraphs: The Althing, the national parliament of Iceland, was founded earlier (930 AD), so it is the oldest legislature in the world still existing. However, the Althing did not function as a legislature for four centuries, and its role as a "primary" legislature is modern.

paragraphs: Other parliaments have copied the UK and work similarly. They have three levels - a lower house which makes the law, an upper house which reviews the law (Decides if they like it or not, and suggest changes to it), and a head of state who is mostly for show and who starts and ends each year of parliament. The Prime Minister is almost always the person whose party has the most seats, but if the lower house does not think he is doing a good job they can call a vote of no confidence and ask him to leave his job as Prime Minister or have an election.

paragraphs: Sometimes people use the word "parliament" to describe a legislature, even if it is not a real parliament. A "parliament" is a type of legislature which has a Prime Minister.

paragraphs: A parliament is a lot like a congress but a congress cannot ask the head of the government to leave his job. Also, a congress runs for a number of years according to the country's constitution, but a parliament can be stopped as long as enough members agree. Elections are held after this happens.


title: Turing test

paragraphs: The Turing test is a test to see if a computer can trick a person into believing that the computer is a person too. Alan Turing thought that if a human could not tell the difference between another human and the computer, then that computer must be as intelligent as a human.

paragraphs: A person has a telegraph, and is connected to two communication partners. One of the two correspondents is a machine. The person can ask anything, with the telegraph. If the person cannot tell which of the two is the machine more than 50% of the time, then the machine is said to be "intelligent" (or smart).

paragraphs: Later on, people narrowed down the test. A human is unlikely to know everything. Therefore, both the human and the machine would be specialists in some field of knowledge. So would the person asking.

paragraphs: As of 2009, no one has made a computer that can pass the Turing test. However, Elbot came close to 30%.

paragraphs: The comic strip Dilbert makes several mentions to the PHB (Pointy Haired Boss) failing the turning test.


title: Fuel

paragraphs: A fuel is a substance that is changed in some way to produce heat, electricity, or other forms of energy. This is usually by being burnt, although there are exceptions, such as nuclear fuel. Fuel can be divided into two main types: fossil fuels and other fuels.

paragraphs: There are several kinds of fossil fuels:

paragraphs: Some people do not want us to use fossil fuels because they may pollute the environment. Because all fossil fuels are made out of carbon, burning them makes carbon dioxide. Some people think that too much carbon dioxide in the air may cause a greenhouse effect. Fossil fuels are also non-renewable, or renew extremely slowly (thousands of years). This means that we will eventually run out of fossil fuels.

paragraphs: Other fuels are not made from fossils. Some of these, like nuclear and hydrogen, do not have carbon in them. Others, like wood or ethanol, do have carbon in them. Some examples of these fuels are:

paragraphs: These fuels are renewable. This means that we can make more of them if we run out. For instance, if we run out of ethanol, we can grow some more corn and make some more ethanol.


title: Estonia

paragraphs: Estonia (), officially the Republic of Estonia () is a small country in the Baltic Region of Northern Europe. The capital city is Tallinn. Estonia's neighbors are Sweden, Finland, Russia and Latvia. Its population is 1,332,893.

paragraphs: The territory of Estonia has the mainland and 2,222 islands in the Baltic Sea.

paragraphs: People have lived in Estonia since at least 9,000 BC. The oldest known settlement in Estonia is the Pulli settlement, which was on the banks of the Pärnu River.

paragraphs: Estonia became independent from Russia in 1920 after a brief War of Independence at the end of World War I. During World War II (1939–1945), Estonia was occupied by the Soviet Union and Germany. It then became the Estonian Soviet Socialist Republic and lost its independence.

paragraphs: Estonia had its independence restored in 1991. It became a member of the North Atlantic Treaty Organization (NATO) on 29 March 2004. It joined the European Union on 1 May 2004.

paragraphs: Estonia is bordered to the north by the Gulf of Finland with Finland on the other side, to the west by the Baltic Sea with Sweden on the other side, to the south by Latvia (343 km), and to the east by Lake Peipus and Russia (338.6 km).

paragraphs: Average elevation reaches only . The country's highest point is the Suur Munamägi in the southeast at .

paragraphs: Estonia has many forests, almost 50% of the land is covered with forests. The most common tree species are pine, spruce and birch. Estonia has over 1,400 lakes and over 2,000 islands. The longest rivers are Võhandu (), Pärnu (), and Põltsamaa ().

paragraphs: Mammals in Estonia include the grey wolf, lynx, brown bear, red fox, badger, wild boar, moose, red deer, roe deer, beaver, otter, grey seal, and ringed seal. The critically endangered European mink has been successfully reintroduced to the island of Hiiumaa. The rare Siberian flying squirrel is present in east Estonia.

paragraphs: Over 300 bird species have been found in Estonia. These include the white-tailed eagle, lesser spotted eagle, golden eagle, western capercaillie, black and white stork, many species of owls, waders, geese and many others. The Barn swallow is the national bird of Estonia.

paragraphs: Protected areas cover 18% of Estonian land and 26% of its sea territory. There are 5 national parks, 159 nature reserves, and many other protection areas.

paragraphs: The Riigikogu is the name of the parliament in Estonia.

paragraphs: Since administrative reform in 2017, there are in total 79 local governments. This includes 15 towns and 64 rural municipalities. All municipalities have equal legal status and form part of a county, which is a state administrative unit.

paragraphs: According to speedtest.net Estonia has one of the fastest Internet download speeds in the world with an average download speed of 27.12 Mbit/s.

paragraphs: Estonia won the Eurovision Song Contest in 2001 with the song "Everybody" performed by Tanel Padar and Dave Benton. In 2002, Estonia hosted the event.

paragraphs: The Estonian National Day is the Independence Day celebrated on 24 February. This is the day the Estonian Declaration of Independence was issued. , there are 12 public holidays and 12 national holidays celebrated each year.

paragraphs: The following are links to international rankings of Estonia.


title: Republic of Cyprus

paragraphs: The Republic of Cyprus is a member state of the European Union. It is in Asia, but it is often associated with Europe because of the culture and history of the people. It is also closer to Africa than to Europe. The capital is Nicosia. Most of the population speaks Greek and Turkish.

paragraphs: Cyprus is the only place outside England where an English royal wedding took place. That was the wedding of Richard I and Berengaria of Navarre on 12 May 1191.

paragraphs: Cyprus gained independence from the British Empire in 1960. The UK, Turkey and Greece became guarantor powers of the island.

paragraphs: In July 1974, Turkey invaded Cyprus. Since then the northern part of the island has been under Turkish control. The Turkish Republic of Northern Cyprus became independent in 1983 but it is recognised only by Turkey. When entering by aeroplane, a short stop is made at an airport in mainland Turkey.

paragraphs: The present situation came about because Cyprus, historically Greek, was conquered and became part of the Ottoman Empire from 15701914. The British administered it from 1878 until 1960. Likewise, Greece had been part of the Ottoman Empire for several centuries. Negotiations for a unified island have been held several times without success.

paragraphs: In 2004, Cyprus joined the European Union. On 1 January 2008 Cyprus adopted the Euro, the single European currency. Northern Cyprus accepts Turkish lira, and sometimes the Euro or United States dollar.

paragraphs: Cyprus is the third largest island in the Mediterranean Sea, after the Italian islands of Sicily and Sardinia.

paragraphs: There are two mountain ranges, the Troodos Mountains and the smaller Kyrenia Range. The Pedieos River is the longest on the island. The highest point on Cyprus is Mount Olympus at .

paragraphs: The Republic of Cyprus is only on the southern two-thirds of the island (59.74%). The Turkish Republic of Northern Cyprus is the northern third (34.85%) and rest are Akrotiri and Dhekelia owned by the British.

paragraphs: The Republic of Cyprus is a constitutional presidential republic. Each president is elected for a five-year term. The president has a lot of power. Cyprus is the only member of the European Union that is governed by a presidential system of government. It is one of few countries (along with San Marino) to have had a democratically-elected communist government, in office from 2008 until 2013. The current governing party is the Democratic Rally.

paragraphs: The Republic of Cyprus is divided into six districts: Nicosia, Famagusta, Kyrenia, Larnaca, Limassol and Paphos. These are not the same as those of Northern Cyprus.


title: Latvia

paragraphs: Latvia is a country in Northern Europe. The capital is Riga. It is one of the Baltic States, together with Estonia in the north and Lithuania in the south. Latvia's neighbours to the east are the countries Russia and Belarus. Latvia is split into four parts called Kurzeme, Vidzeme, Zemgale, and Latgale.

paragraphs: People from Latvia are called Latvians. They speak the Latvian language, which is a little like the Lithuanian language, though not close enough to be understood.

paragraphs: Latvia was settled by the Baltic tribes thousands of years ago. They mainly fished, hunted, and traded.

paragraphs: German traders and crusaders came to Latvia at the end of the 12th century. Latvians lost control of their homeland. Over the next 800 years, Germans, Danes, Swedes, Poles, and Russians all invaded Latvia. Latvia finally became independent in 1918.

paragraphs: The Soviet Union invaded Latvia during World War II and killed or took away many of its people to Siberia and other places far away from their homes. The Soviet Union then invaded again and occupied Latvia until 1991, when the Soviet Union fell apart and Latvia became an independent country again.

paragraphs: In Copenhagen on 13 December 2002, Latvia and nine other countries were invited to join the European Union. On 20 September 2003, Latvians held an election to vote on joining. Two thirds of Latvians voted to join, and on 1 May 2004 Latvia became a member of the EU.

paragraphs: Latvia has been a NATO member since 29 March, 2004.


title: Lithuania

paragraphs: Lithuania is a country in northern Europe on the eastern shore of the Baltic Sea. Lithuania is a member of the European Union, NATO, and several other organizations.

paragraphs: About 3,000,000 people live in the country. The official language is Lithuanian which is spoken by more than 82% of the people. Vilnius is the capital and largest city.

paragraphs: The colors of the Lithuanian flag are yellow (at the top), for the sun, green (in the middle), for the fields, and red (at the bottom), for the blood of Lithuanians fighting for its independence.

paragraphs: Lithuania began to turn into a country in the 7th–9th centuries from Baltic nations group. The Balts, the ancestors of Lithuanians and Latvians, came to area between Nemunas, Daugava rivers and the Baltic Sea, from a supposed original homeland of the Proto-Indo-European languages. Many scientists think they came there sometime in the 3rd millennium BC.

paragraphs: The traditional date of the beginning of the country is 1236 when the Lithuanians won the Battle of Šiauliai (Battle of Sun).

paragraphs: Lithuania (at that time - The Grand Duchy of Lithuania) made a Treaty with Poland in 1569. The country was taken over by the Russian Empire in 1795, ending the Polish-Lithuanian Commonwealth. It got back its independence on February 16, 1918. It was taken over by the Soviet Union on June 16, 1940, by Nazi Germany from 1941-1944 and again the Soviet Union from 1944-1990. Lithuania re-declared its independence on March 11, 1990. Currently Lithuania is an independent, semi-presidential, democratic republic.

paragraphs: Lithuania has been a member of NATO and the European Union since 2004.

paragraphs: Lithuania is a semi presidential republic, that restored its independence and democracy in 1990. Since then, very important reforms were made and Lithuania is now declared as a democratic state that grants the human rights.

paragraphs: The Constitution that was adopted in 1992 declares that the leader of the country is the President, who must be elected to take office. The elections are held every 5 years. If the President breaks their oath, they can be forced to resign by the Parliament. The President also represents Lithuania abroad and is the commander-in-chief.

paragraphs: The legislative power of Lithuania is called the Seimas, or Parliament. There are 141 members of Seimas who are elected for 4-year-terms. Seimas passes the laws that must be executed by the government, that is formed in Seimas and it must be accepted by the President. The Prime Minister is set and fired by the President.

paragraphs: The justice is under the power of the courts. The supreme court in Lithuania is the Constitutional Court.

paragraphs: Lithuania is divided into 10 counties, 60 municipalities and 500 elderates. The counties are:

paragraphs: The county governor rules the county. He or she must be appointed by the central government. Municipalities are governed by the Municipal Councils that are elected for 4 year terms. The head of a municipality is the mayor. The elderates are governed by the elders. The elders are appointed by the municipal councils.

paragraphs: Lithuania is a country in northern Europe. Its neighbours are Poland in the southwest, Russia (Kaliningrad) in west, Latvia in north and Belarus in the east. Lithuania borders the Baltic Sea and 99 kilometres of its coast belong to Lithuania. The highest hill is Aukštojas (294 metres high), the largest lake is Drūkšiai Lake. 31% of the land is suitable for farms.

paragraphs: Lithuania is divided into 5 cultural regions according to their past and traditions:

paragraphs: Lithuania has a fast growing economy. It grew up to 7% in the first quarter of 2008.

paragraphs: GDP per capita, based on purchasing power parity is estimated to be $19,730 in 2008. The nominal GDP per capita is estimated to be $14,213 at the same year. According to these numbers, Lithuanian per capita GDP reaches only 61% of EU average. However, it is impressive that only in 8 years, since 2000 it grew up from 30% of EU average.

paragraphs: Emigration still creates a problem. According to the official data, emigration in 2006 was 30% lower than previous year, with 3,483 people leaving in four months.

paragraphs: About 80% of people in Lithuania are Lithuanians. There are large national minorities:

paragraphs: Lithuanian is spoken by 82% of the people and it is the only official language. Polish is used mostly in Vilnius County where Polish politicians are elected to represent the Polish minority. The documents and street names must be in Lithuanian.

paragraphs: The biggest cities are Vilnius, 542,287 people, Kaunas, 358,107 people, and Klaipėda, 185,899 people.

paragraphs: The nursery schools and the kindergartens are the first-level education forms. However, they are not compulsory. The children start attending the primary school at age 7, where educational programs last for 4 years; then they must start attending secondary school (5th to 10th grades). After finishing 8th or 10th grade, the student can continue learning at the high school or choose courses at the vocational college. The students who finish the high school can join colleges and universities. Higher education is free for the students whose annual median of grades is 8 or higher. The others have to pay 500 Litass per semester at least.

paragraphs: The higher education schools are universities and colleges. The main universities are:

paragraphs: Lithuanians can choose from many television and radio stations. The first radio station was started in 1926 in Kaunas. The first television station started in 1957. The main radio stations are:

paragraphs: The oldest legal newspaper in Lithuania is the Polish Kurier Wilenski. It was first published in the 18th century and is now only popular with the Polish community. The biggest selling newspapers are:

paragraphs: Internet news portals are very popular in Lithuania. They have the latest information and also let people make comments. The most popular Internet sites with news and information are:


title: Malta

paragraphs: Malta is a country in Europe. It is an island near the center of the Mediterranean Sea, south of Sicily. The capital of Malta is Valletta. Around 400,000 people live in Malta and it is one of the most densely populated countries in the world. Its many cities and towns grew close to each other over time.

paragraphs: Maltese is the national language of Malta. Maltese and English are the official languages in line with the constitution of the country. A majority of the people of Malta can speak three languages; Maltese, English and Italian.

paragraphs: Malta had its own currency, called the Maltese Lira until 2008. The Maltese "Lira" was better known as the Maltese "Pound" because of the strong links to the United Kingdom. One Maltese Lira consisted of 100 "cents". In 2008 Malta joined the Euro countries in adopting the Euro as the National Currency.

paragraphs: People have lived in Malta since at least 5200 BC. The island has some key archaeological sites dating from early times.

paragraphs: Malta became well known as the base of the Knights Hospitaller. They moved to Malta after being forced to leave Palestine and then Rhodes, in Greece. In 1565 they survived a great attack by the Ottoman Empire. The history of the knights at Malta continued the strong Roman Catholic beliefs in the country that were started by the Norman and Spanish rulers.

paragraphs: In 1798, Napoleon took control of Malta. The French rule was not popular and in 1800 Maltese rebels invited the British Royal Navy to come to the island. This led to 200 years as a British colony and independent Commonwealth member.

paragraphs: During World War II, Malta was attacked this time by the Axis forces. The entire island was symbolically given the George Cross for heroism.

paragraphs: Malta became independent in 1964 and a republic in 1974. In 2004 Malta joined the European Union and in 2008 Malta joined the Euro.


title: Comoving distance

paragraphs: In normal cosmology, 'comoving' distance or 'proper distance' is one of several distances measured by cosmologists to define distances between objects.

paragraphs: To talk about the shape of the Universe, scientists want to forget that the Universe is expanding. So they separate the shape from time and pretend that the Universe is not expanding. They remember that, really, the Universe is expanding, but they write this in a variable called the scale factor. Then, the distances they talk about, while putting the scale factor to the side, are called comoving distances. When they think about the Universe using comoving distance, they think of the Universe as not expanding. This way, some calculations are easier.

paragraphs: When the part of the Universe which we can see today started, it was very small. Everything in this part of the Universe was much closer together than today. It was also very hot and photons (particles of light) were moving in different directions. Light moves very fast, but the light speed is limited and the Universe was expanding very fast.

paragraphs: Think of two ants on the surface of an expanding balloon. One ant starts moving towards another, but the balloon itself is also expanding. After a long time the balloon starts expanding more slowly. Eventually one ant reaches another. That's like photons in our universe. Some of the light from the stars you see at night traveled for billions of years to reach your eye. Surprisingly, it started very close to where you were (or the atoms of which your body consists), but just could not keep up with the universe expansion. Of course, if something else started out very close to where you were, but was not traveling toward you, it would be very far away from you now because of the expansion.


title: Shaanxi

paragraphs: Shaanxi (Chinese:陕西, also sometimes called Shenshi) is a province in east China. The word "Shaan" (viz Shanzhou) is a place in Henan Province. "Xi" means "west". So "Shaanxi" means "the place to the west of Shaan".

paragraphs: Although in pinyin, "Shaanxi" is spelled exactly the same as "Shanxi", the only difference in how the two words are pronounced is that the first syllable in "Shanxi" is said using the first tone in Mandarin, while the first syllable in "Shaanxi" is said with the third tone. Since tone markers are not usually used to show how to pronounce the two different names, the first word in "Shaanxi" is spelled using the Gwoyeu Romatzyh method instead, which indicates tones by adding extra letters to a syllable.

paragraphs: The river Wei He runs across it. It has a large population of more than 30 million people. The capital of Shaanxi is Xi'an. It abbreviates as Shan (陕) or Qin (秦), also known as SanQin (三秦, meaning "Three Qins").

paragraphs: January 23, 1556 – A massive earthquake, measuring 9.0 on the Richter scale, strikes Shaanxi, killing over 850,000 people. This is the most devastating earthquake in recorded history.

paragraphs: Shaanxi Province is divided into ten municipalities:


title: Lisbon

paragraphs: Lisbon is the capital city of Portugal. It is the largest city of Portugal. The city has a population of about half million people. In Lisbon's urban area live around 2.8 million people, being the 10th-most populous urban area in the European Union.

paragraphs: Lisbon is placed on the right bank (western) of the Tagus River, near the outfall. It has a pleasant climate and has about 220 days of sunshine each year. There are many beautiful beaches close to the city. There are also many seafood restaurants, historical sites and monuments. Lisbon is one of the oldest cities in the world.


title: Surfing

paragraphs: Surfing is a water sport done in the ocean or sea. The surfer uses their surfboard to catch a wave and ride in towards the shore.

paragraphs: Surfing was invented by the Polynesians at least 4000 years ago. It has become a popular sport among both men and women of all ages. With lifestyles and regimens freer than those of most sports, surfers comprise a unique culture. Though surfing is practiced in many other Pacific nations, its center remains Hawaii, where many rounds of the international surfing championships (the ASP) are held annually. Surfing is popular in Australia, the US, and Northern Europe.


title: Lyon

paragraphs: Lyon is a city in the southeast of France. It is the third-largest city in the country (behind Paris and Marseille), with about 513,000 people living there in 2015. It is the second largest "metropolis", or metro area, in France (behind only that of Paris), with about 2.3 million people in 2014.

paragraphs: In ancient history, the name of Lyon was "Lugdunum". Someone who lives in Lyon is called a "Lyonnais" (male) or a "Lyonnaise" (female) in French.

paragraphs: Lyon has a humid subtropical climate ("Cfa" in the Koeppen climate classification). It is between the Rhône and the Saône. It is about west of the Italian border.

paragraphs: The central part of Lyon, located on the peninsula between the Rhône and the Saône, was named a World Heritage Site by UNESCO.