title: Insect

paragraphs: Insects, are a class in the phylum Arthropoda. They are small terrestrial invertebrates which have a hard exoskeleton.

paragraphs: Insects are the largest group of animals on earth by far: about 926,400 different species have been described. They are more than half of all known living species. They may be over 90% of animal species on Earth.

paragraphs: New species of insects are continually being found. Estimates of the total number of species range from 2 million to 30 million.

paragraphs: Most, but not all, insects have six legs; and most have wings. Insects were the first animals capable of flight.

paragraphs: As they develop from eggs, insects undergo metamorphosis. Insects live all over the planet: almost all are terrestrial (live on land). Few insects live in the oceans or in very cold places, such as Antarctica. The most species live in tropical areas.

paragraphs: Some people call all insects "bugs", but this is not correct. Only some insects are true bugs, which is a particular order of insects. People who study insects are called entomologists.

paragraphs: Insects have exoskeletons (skeletons on the outside). Their skeletons are made out of thin, hard pieces or plates, like armour, made of chitin. All together, these pieces make a hard layer around the insect’s body. The exoskeleton protects the insect.

paragraphs: The body of an insect has three main parts: a head, a thorax, and an abdomen. On the head are an insect’s compound eyes, its two antennae (they feel and smell things), and its mouth.

paragraphs: On the thorax, insects have wings and legs. All insects have six legs (three pairs of jointed legs) and usually four wings (two pairs).

paragraphs: The abdomen is the back part of the insect. Inside the abdomen is the stomach, the heart, and the excretory system where body wastes pass out of the insect. Bees also have a stinger at the back of the abdomen.

paragraphs: Just like our muscles connect to our bones to make us walk and stand up, the muscles of an insect connect to the exoskeleton to make it walk and move. Their muscles are on the "inside" of their skeleton.

paragraphs: Insects are cold-blooded, which means that they cannot control their body temperature. This means that insects are not good at surviving the cold, at any rate out in the open. In the winter, many insects go into something called diapause, which is the insect version of hibernation. Some insects, like cockroaches, cannot go into diapause and they will die if it gets too cold outside. This is why cockroaches love living in people's warm houses.

paragraphs: Insect respiration happens without lungs. There is a system of internal tubes and sacs through which gases diffuse or are actively pumped. Air is taken in through openings on the sides of the abdomen called spiracles. Oxygen gets to tissues that need it through their trachea (element 8 in diagram).

paragraphs: Many insect larvae live in water. Many of those have gills that can extract oxygen dissolved in water. Others must rise to the water surface to get air which may be held or trapped in special parts of their body.

paragraphs: Adult insects use oxygen at a high rate when they fly. They need it for the flight muscles, the most active tissue known in biology. The flight muscles use oxygen at a huge rate: 100 ccs of oxygen for every single cc of tissue per hour. With this system, the greatest diameter a muscle could have (and still consume oxygen at this rate) is about 0.5 cm. Even with special extra arrangements, insects cannot get larger than about 11 cm long. The largest insect bodies are about as big as a mouse.

paragraphs: Some insects also use a molecule called haemocyanin, which does the same job as haemoglobin does in vertebrates (but less efficiently). The insect circulatory system has no veins or arteries. The 'blood' is called haemolymph, and moves around in the space called the haemocoel. The organs sit in the haemocoel and are bathed in the haemolymph. The 'heart' is little more than a single tube which pulses (squeezes).

paragraphs: Insects start life as an egg. Usually a female (mother) insect lays eggs, but a few species have live birth (the eggs develop inside the mother). The eggs are small; but they can usually be seen with the naked eye.

paragraphs: Although the adults are larger, they do need a magnifying glass or a binocular microscope to see the details. A professional entomologist uses a binocular microscope to identify insects, plus a printed reference work. There are far too many insects for anyone to remember them all, and most entomologists specialise in just one or two orders.

paragraphs: After the eggs hatch, two kinds of development may occur. Some insects have what is called 'incomplete metamorphosis'. This means that a small insect, called a nymph comes out of the egg, and the nymph looks almost the same as the adult insect. As the nymph grows, it does not change the way it looks, but only how big it is. It goes through a number of stages, called 'instars'. Grasshoppers grow in this way.

paragraphs: Other insects have complete metamorphosis, which means that the small larva which comes out of the egg looks very different from the adult insect. Insects that have complete metamorphosis usually come out of the egg as a larva, which usually looks like a worm. The larva eats food and gets bigger until it turns into a pupa. Butterfly pupae (plural for pupa) are often inside cocoons. Inside the cocoon the insect changes the way it looks and often grows wings. When the cocoon opens, the adult insect comes out. Many insects have complete metamorphosis, for example beetles, butterflies and moths, and flies. The adult stage of development is called the imago.

paragraphs: The oldest known insect fossil is the Devonian "Rhyniognatha", from the 396 million year old Rhynie chert. It may have superficially resembled a modern-day silverfish insect. This species already possessed mandibles of a type associated with winged insects, suggesting that wings may already have evolved at this time. Thus, anatomical recrds suggest the first insects may have appeared earlier, in the Silurian period. Genomic analysis puts their origin even further back in the Ordovician period.

paragraphs: In 2008, researchers uncovered what they believe is the world's oldest known full-body impression of a primitive flying insect, a 300 million-year-old specimen from the Carboniferous period.

paragraphs: The origins of insect flight remain obscure, since the earliest winged insects currently known appear to have been capable fliers. Some extinct insects had an additional pair of winglets attaching to the first segment of the thorax, for a total of three pairs. It seems the insects were not a particularly successful group of animals before they evolved wings.

paragraphs: Upper Carboniferous and Lower Permian insect orders include both living groups and a number of Palaeozoic groups, now extinct. During this era, some giant dragonfly-like forms reached wingspans of making them far larger than any living insect.

paragraphs: This gigantism may have been due to higher atmospheric oxygen levels, which allowed increased respiratory efficiency. The lack of flying vertebrates could have been another factor. Many of the early groups became extinct during the PermianTriassic extinction event, the largest mass extinction in the history of the Earth, around 252 million years ago.

paragraphs: Different kinds of insects can be divided into groups called orders. There are many insect orders (about 29). The biggest insect orders are listed below:

paragraphs: All these groups except one (Odonata) are strongly connected with plants as a source of food.

paragraphs: Spiders, scorpions, and similar animals are not insects; they are arachnids. Arachnids are arthropods that have four pairs of legs. Centipedes are also arthropods, but not insects: they are in a subphylum called the Myriapoda.

paragraphs: This taxonomy lists some of the better known groups of insects.

paragraphs: Pests can be harmful to people in different ways. Some are parasites, such as lice and bed bugs. Some of these parasite insects can spread diseases, such as mosquitoes spreading malaria.

paragraphs: Other pest insects do not directly hurt people. Termites and some beetles eat wood and sometimes eat buildings, such as houses. However, termites also help break down the trees and branches that fall on the forest floor. Many insects eat agricultural products (plants meant for people to eat). Grasshoppers are one example of pest insects that eat plants in agriculture.

paragraphs: Some insects are useful to us. Bees make honey. The larvae of some moths make silk, which people use to make clothing. In some parts of the world, people actually eat insects. Eating insects for food is called entomophagy.

paragraphs: Many bees and flies pollinate plants. This means the insects help the plants make seeds by moving pollen from one flower to another. Some good insects eat pest insects, such as lady beetles (or ladybirds or ladybugs) eating aphids. Many insects eat dead plants and animals.

paragraphs: People often use poisons called insecticides to kill pest insects. Insecticides do not always work. Sometimes the pest insects become resistant to the insecticides, which means the insecticides do not hurt them anymore. Both the Colorado potato beetle and the diamondback moth are insects that are resistant to many insecticides.

paragraphs: Insecticides do not only kill pest insects; sometimes many helpful insects are killed too. When helpful insects are killed, such as those that eat pest insects, the pest insects may come back in larger numbers than before because they are not being eaten by helpful insects anymore.


title: Computer jargon

paragraphs: Computer jargon means words to do with computers and surrounding topics. Knowing what these words mean can help people know more about computers. Most people use these words to discuss computer ideas, but some people use these words to impress others (also known as buzzwords).


title: Million

paragraphs: One million (1,000,000), or one thousand thousand, is the natural number after 999,999 and before 1,000,001. The name is derived from Italian, where was 1,000, and 1,000,000 became a ""milione"", as 'a large thousand'.

paragraphs: In scientific notation, the number is written as 1×10 or just 10. Physical quantities can also be expressed using the SI prefix when dealing with SI units. For example, 1 megawatt equals 1,000,000 watts.

paragraphs: The word 'million' is common to both the short-scale and long-scale numbering systems, unlike the larger numbers, which have different names in the two systems.

paragraphs: The million is sometimes used in the English language as a metaphor for a very large number, as in 'Never in a million years' and 'You're one in a million', or as hyperbole, as in 'I've walked a million miles'.

paragraphs: "Il Milione" is the title of Marco Polo's narration of his travels in China. The name is supposed to come from Polo's nickname after his tales of riches and multitudes.


title: 1000 (number)

paragraphs: A thousand (1000, one thousand or 1,000) is the natural number after 999 and before 1001. One thousand thousands is known as a million.

paragraphs: In Roman numerals, 1000 is written as M.


title: Gross domestic product

paragraphs: In economics, gross domestic product (GDP) is how much a place produces in an amount of time. GDP can be calculated by adding up its output inside the borders of that country.

paragraphs: To find the GDP of a country, one adds up all consumer spending (C), all investment (I), all government spending minus taxes (G), and the value of exports minus imports ("X – M"). This is shown by the equation:formula_1 This measure is often used to find out how healthy a country is; a country with a high value of GDP can be called a large economy. The United States has the largest GDP in the world. Germany has the largest in Europe, Nigeria in Africa and China in Asia.

paragraphs: There are different ways to calculate the GDP. Nominal GDP is the total amount of money spent on all new and final goods in an economy, real GDP (adjusting for changes in prices) tries to correct this number for inflation. For example, if the prices rise by 2% (meaning, everything costs 2% more) and the nominal GDP grows by 5%, the real GDP growth is only increased by 3%.

paragraphs: GDP per capita is the total income of a country, divided by the number of inhabitants. It shows how rich people, on average, are.

paragraphs: The GDP measure is different from gross national product (GNP) in that GNP = GDP + net income from assets in other countries (net income receipts).

paragraphs: When the gross domestic product is evaluated at the current market prices, it is called the nominal GDP. It includes changes in prices which makes it different from the real GDP. These changes can be due to inflation or price fluctuations. It can be measured in one of three different ways. The "income approach" uses the total of all income from businesses and individuals in a single year. The "expenditure approach" uses the market value of all goods purchased in a single year. The "production approach" is based on the total production in a single year.


title: Cricket

paragraphs: Cricket is a sport which is played between two teams of eleven players each. One team, which is batting, tries to score runs (points), while the other team is fielding, and tries to prevent this. Runs are scored by hitting the ball, which is thrown by a player from the fielding team to a player from the batting team, across the boundary, or by the batting team's players running between two areas of the field called the batsmen's grounds as many times as possible before the fielding team successfully hits a wicket (set of sticks) in either of the grounds with the ball to get them out.

paragraphs: The wickets are sets of three small, wooden posts that are at each end of a rectangle of short grass called 'the pitch', which is 22 yards long. The pitch is inside a much larger oval of grass called the 'area of play'. The area of play is a 30 yard circle inside the cricket ground or stadium. When a player is out, a teammate will replace them in the field. When a team no longer has enough "not-out" players left to score, then the other team gets the chance to try to score. In shorter games of cricket, a team may also have to stop batting when the ball has been thrown to their players a certain number of times. After both teams have had enough chances to score, the team with the most runs wins.

paragraphs: The game started in England in the 16th century. The earliest definite reference to the sport is in a court case of 1598. The court in Guildford heard a coroner, John Derrick, that when he was a scholar at the "Free School at Guildford", fifty years earlier, "he and diverse of his fellows did run and play [on the common land] at cricket and other players". Later, the game spread to countries of the British Empire in the 19th and 20th centuries.

paragraphs: Today, it is a popular sport in England, Australia, India, Pakistan, Sri Lanka, Bangladesh, South Africa, New Zealand, the West Indies and several other countries such as Afghanistan, Ireland, Kenya, Scotland, the Netherlands, and Zimbabwe.

paragraphs: There are two teams: The team bowling has 11 players on the field. The team batting has two players, one at each end of the pitch (also sometimes called the wicket).

paragraphs: The captain of the bowling team chooses a bowler from his team; the other players are called 'fielders'.

paragraphs: The bowler runs towards his wicket, and bowls towards the batsman at the other wicket.

paragraphs: The batsman is trying to defend the wicket from getting hit with the ball. He does this with a bat. When he hits the ball with his bat, he may run toward the other wicket.

paragraphs: There are different ways that a batsman can get out. The most common ways are:

paragraphs: When a batsman is out, another comes onto the field to take his place. The innings is over when ten wickets are taken (i.e. ten of the eleven batsmen are out). After this, the team which was the 'fielding' team becomes the 'batting' team. They now have to score more runs than the other team managed to score. If they score more runs before ten wickets are taken, they win. If they do not, the other team wins.

paragraphs: In a one-day game, each side has one innings, and innings are limited to a certain number of overs. In longer formats each side has two innings, and there is no specific limit to the number of overs in an innings.

paragraphs: Cricket is popular in many countries, mostly in Commonwealth countries.

paragraphs: The countries where cricket is most popular compete in international matches (games between countries) that last up to 5 days, which are called Test matches. Those countries are England, Australia, West Indies, South Africa, New Zealand, India, Bangladesh, Zimbabwe, Ireland, Afghanistan and Sri Lanka. The West Indies are a group of Caribbean countries that play together as a team. Several other countries have more junior status. The test match idea was invented by teams from England and Australia in the 19th century.Ireland and Afghanistan are the new teams which can play Test cricket.

paragraphs: Cricket is also played in Kenya, Canada, Bermuda, Scotland, Holland and Namibia; the national teams of those countries can play one-day international matches, but do not play test matches.

paragraphs: A cricket field is where cricket is played. It is circular or oval-shaped grassy ground. There are no fixed dimensions for the field. Its diameter usually varies between 450 feet (137 m) to 500 feet (100 m).

paragraphs: Test matches are the top international matches played between countries. The main point of test cricket is to test young players. The countries permitted to play test matches are accredited by the ICC: the International Cricket Council. The ten countries are listed below, with 'West Indies','England' counting for this purpose as a country. Tests last for up to five days (This is why many also call it "5 day cricket.") and can still end in a draw match : it is the longest format of cricket.

paragraphs: Test Playing Nations "in order of first dates":

paragraphs: Called counties in England, and states in Australia and islands in the West Indies. These are three or four day matches.

paragraphs: In these games, the length is determined by the number of overs, and each side has one innings only. A special formula, known as the 'Duckworth–Lewis method' is applied if rain reduces the time for play. It calculates the target score for the team batting second in a limited overs match interrupted by weather or other circumstance.

paragraphs: ODIs are usually restricted to 50 overs batting for each side and each bowler can bowl up to 10 overs maximum. The highest team score is England 481-6 against Australia in June 19, 2018. The highest individual score is 264 off 173 balls by Rohit Sharma for India against Sri Lanka.

paragraphs: Twenty20 cricket has 20 overs for each side and each bowler can bowl up to 4 overs maximum unlike 10 overs in an ODI match. The highest team score is 263/5 by Royal Challengers Bangalore (RCB) against Pune Warriors India (PWI) in the 2013 IPL season. The highest individual score is 175* off 69 balls by Chris Gayle for RCB in the same match.

paragraphs: In cricket there are two special kinds of average, used to measure how good a player is:

paragraphs: There is a separate set of averages for each type of cricket listed above.


title: Track and field athletics

paragraphs: Track and field is part of the sport of athletics. Athletics is a collection of sport events that includes running, jumping and "throwing". Track and field events take place in a sports stadium, either on the running track, or on the field inside the running track. These tracks are generally made up of synthetic rubber – rubber particles bound with latex or polyurethane. Other athletics events that are not track and field, include cross country running, road running, marathon running, and race-walking - these events take place outside a sports stadium.

paragraphs: Athletics is a very common sporting event over the world. Athletics is a combination of different sports, generally running, jumping and throwing events. Running events include marathons, hurdle races, long distance and short distance events. Some jumping events are high jump, long jump, triple jump and pole vault. Throwing events involve javelin throw, discus throw, hammer throw and shot put.

paragraphs: There are also events that combine parts of running, jumping, and throwing. One of these is the "decathlon", which includes two short-distance races, a mile run, a hurdles race, javelin, discus, shot-put, high jump and pole vault.

paragraphs: All participants are timed or have a distance measured and this is their end result. Participants train hard for an event and always aim to better their results.

paragraphs: Athletics is a sport that people take part in all over the world. It is a sport that is most common between young children up to younger adults. Athletics can be played for enjoyment, but it can also be a competitive sport. Athletics is also an event in the Olympic games.


title: Badminton

paragraphs: Badminton is a sport for two or four( "singles" or "doubles") people. The game is either one player against one player or a team of two players against another team of two players. Players use rackets to hit a shuttlecock over a net but if it goes too far it will be an out.

paragraphs: The aim of the game is to hit the shuttlecock over the net in a way that the other player or pair cannot hit it back properly before it hits the floor. Every time this is done, the player or pair gets one point. They also get to serve. The first player or pair to reach 21 points wins a game.

paragraphs: The winner of the match is the first to win 2 sets.

paragraphs: Badminton traces its history to a game called George Cajoles, which was played in Pune, India in the 19th century by the British military officers stationed there. This game was taken by retired officers back to England where it developed and quickly grew in popularity.

paragraphs: In 1877, the first set of written rules were arranged by the newly formed Bath Badminton Club. The All England Open Badminton Championships, the first badminton competition in the world, was held in 1899.

paragraphs: Badminton has been an Olympic sport since 1992 Summer Olympics in Barcelona.

paragraphs: Although badminton originated in England, it is mainly played in countries of Asia such as China, Nepal, Indonesia and the Republic of Korea that now dominates this sport.


title: Chemical warfare

paragraphs: Chemical warfare means using chemical compounds in war to injure or kill people. The chemicals used for chemical warfare are poisonous.

paragraphs: Chemical warfare has been used since the Stone Age. Since 1899, several international laws have said that using chemical weapons is illegal. But chemical weapons have still been used in wars since then.

paragraphs: Chemical weapons are different than regular weapons (like bombs) or nuclear weapons because they do not explode. Some chemical weapons are meant to kill people; they do this by poisoning them. Other chemical weapons are meant to "incapacitate" people (make them unable to fight back). They do this by causing pain, injuries, or sickness.

paragraphs: Chemical warfare does not include using living organisms (like anthrax bacteria) to make people sick. That is called biological warfare.

paragraphs: However, some living organisms make toxins (poisons). These toxins are not alive. For example, botulinum toxin is made by a bacteria, and ricin is made by the castor oil plant. Because botulinum toxin and ricin are not alive, using them to make people sick is called chemical warfare. This is explained in the Chemical Weapons Convention (CWC). The Convention also says that any toxic chemical is a chemical weapon unless it is used for legal reasons.

paragraphs: About 70 different chemicals have been used or stockpiled (saved up) as chemical warfare agents during the 20th century. The Chemical Weapons Convention says that all of these chemicals should be destroyed.

paragraphs: The Chemical Weapons Convention lists three different groups of chemicals. These are chemicals that are poisonous enough to be used as chemical weapons, or chemicals that may be used to make chemical weapons.

paragraphs: Although very basic chemical warfare has been used in many parts of the world for thousands of years, "modern" chemical warfare began during World War I (see the page Chemical weapons in World War I).

paragraphs: Since modern chemical warfare started in World War I, countries have tried to research and make chemical weapons. They have had four main goals:

paragraphs: Chemical warfare was first used during the Stone Age. Stone Age people used poisoned arrows and spear-tips. These were dipped in poisons, like venom from snakes or scorpions. Sometimes they used poisonous plants.

paragraphs: The Ancient Chinese used different forms of poisonous smokes, when they besieged a city to try to take it over.

paragraphs: The Ancient Greeks used a form of burning wood, pitch from plants, and sulphur.

paragraphs: "Main article: Chemical weapons in World War I"

paragraphs: Poison gas was first used in World War I. France was the first country to make this type of gas. However, Germany was the first to use it in battle, on March 15th, 1915. On that day, they used tear gas against France.

paragraphs: The three types of gas used in World War One were:

paragraphs: At first, very basic ways of spreading these gases were used. Even so, many soldiers could be hurt or killed. This was partly because World War I was fought usingtrench warfare, so many soldiers would be in the same place at the same time, and escaping from poisonous gases would be very hard.

paragraphs: Germany was the first country in World War I to use chemical warfare in battle. They simply opened containers of chlorine upwind of enemy soldiers, so that the wind would carry the chlorine gas to their enemies.

paragraphs: Soon after this, the French started using chemical weapons too. They filled artillery projectiles with phosgene and fired them at the Germans. This was a much more effective way of using chemical weapons. It would become the most common way of delivering chemical weapons during World War I.

paragraphs: Chemical weapons were not used very much in World War II, except by the Japanese army during the invasion of China. This was because everybody was afraid that the other side would use weapons like theirs. Also, chemical weapons were not easy to use. They took time to use, and this made it harder for soldiers to move quickly. Also, the raw materials needed to make chemical weapons were not easy to get. This was because World War II was fought in areas which were not connected well by railroads.

paragraphs: During the Iran-Iraq War, Iraq used chemical weapons (Iran did not). Many people believe that Iraq used chemical weapons against the Kurdish people.

paragraphs: The United States has used chemical weapons even after World War II. For example, the U.S. used Agent Orange during the Vietnam War.

paragraphs: It has been reported that many other countries, like the People's Republic of China, Cuba, Egypt, Iran, Israel, North Korea, Pakistan, Sudan, Syria, Taiwan, and Serbia and Montenegro, have chemical weapons.

paragraphs: According to international law, it is wrong to use chemical weapons. Since 1899, there have been many rules that make it illegal to make, import, and use chemical weapons.

paragraphs: The first international law to make chemical warfare illegal was the Hague Convention in 1899.

paragraphs: After World War I, the Geneva Protocol of 1925 made it illegal to use chemical or biological weapons on people.

paragraphs: In 1997, the Chemical Weapons Convention (CWC) was created. As of the end of 2015, 192 countries had agreed to follow the CWC. According to the Organization for the Prohibition of Chemical Weapons, as of October 2015, 90% of the world's chemical weapons stockpiles had been destroyed.

paragraphs: The main types of agents used in chemical warfare are:

paragraphs: If we use chemicals (like Agent Orange or glyphosate) to destroy plants, sometimes human beings may be affected by side effects. But, we will not call it chemical warfare. Chemical warfare covers only direct attacks on human life.


title: Iran

paragraphs: Iran officially the Islamic Republic of Iran (), historically known as Persia, is a country in Western Asia. It is part of the Middle East region. It shares borders with Afghanistan, Armenia, Azerbaijan, Iraq, Pakistan, Turkey, and Turkmenistan.

paragraphs: Tehran is the capital and biggest city. Iran is the eighteenth largest country in the world. It has more than 84.9 million people. Iran has been a member of the United Nations since 1945. It is a member of the Organization of the Petroleum Exporting Countries (OPEC). It is an Islamic republic.

paragraphs: In Iran, Persians, Azerbaijanis, Kurds, Mazandaranis, Gilaks, Lurs and Bakhtiaris make up the nations minority ethnic groups.

paragraphs: In the past, Iran was called "Persia" by people outside of the country. The people that lived there called the country "Iran". The official name was Persia, a region in Iran. The name Persia was used when dealing with other countries and in government papers.

paragraphs: In 1935, Reza Shāh Pahlavi was Shah of Iran. He officially asked foreigners to call the country "Iran". This was done to show that Iran belongs to all the non-Persian Iranians as well as to Persian Iranians. The name Iran means "land of the Aryans". It is used in the ancient book of the Zoroastrians, the Avesta. In the 19th and early 20th century, the name "Aryan" was used by Europeans to mean "all Indo-Europeans". The "Aryan Race" was a term that Hitler used to describe his "Superior" or "perfect" race, but it first meant Iranians. "Aryan" means "noble" in Iranian languages.

paragraphs: Around 500 BC, the area that is now Iran was the center of the Achaemenid Empire. The Greek city states fought against the Persian armies led by Darius the Great and Xerxes. Then Alexander the Great took the country by fighting the Achaemenid dynasty of Persia. He ruled until he died,then the Greek Seleucids ruled until they were defeated by the Parthian Empire which later fought the Roman Empire.

paragraphs: After the Parthians, the Sassanian dynasty (224-651) took over. Other people took Persia by fi\ghting, like the Arabs (7th century), Turks (10th century) and Mongols (13th century). However, Iran has always had a different culture and continued to survive.

paragraphs: The Central Intelligence Agency (CIA) worked in Iran to create 1953 riots which led to the removal of Prime Minister Mosaddegh. The United States and Great Britain then made the Shah Mohammad Reza Pahlavi the most powerful person in Iran, again. The Shah left Iran in 1979 in the face of a revolt. The Iranian government was changed to an Islamic Republic by Islamic Revolution. Soon afterwards, the Iranian Students Movement (Tahkim Vahdat), with the backing of the new government, took over the U.S. Embassy in Tehran. They held most of the diplomats hostage for 444 days.

paragraphs: Relations between the two countries have not been good since. For example, the United States claims that Iran supports terrorist groups against Israel. Iran does not see Israel as a country. Iran, along with most Arab countries, believes that Israel does not have the right to exist. However, Iran has collaborated with the West at times. These deals have been about energy or about fighting terrorism.

paragraphs: Iran fought the Iran–Iraq War in the 1980s. Many foreign countries supported Iraq.

paragraphs: Now, the West is trying to prevent Iran from using nuclear technology, even though Iran is a member of the Nuclear Non-Proliferation Treaty. The International Atomic Energy Agency (IAEA) has reported many times that there is no evidence that Iran is developing nuclear weapons. However, it also says that it can not say for sure that Iran is not doing so in secret.

paragraphs: A December 2007 CIA report on nuclear activity in Iran said that Iran's secret program to get nuclear weapons technology was stopped in 2003. It said that Iran will probably not be able to build a nuclear weapon soon.

paragraphs: Iran has the natural resource of oil. It is a member of OPEC. Oil is one of its main exports. Rice, handicrafts, carpets and crocus are important local products. Iran is the world's largest exporter and producer of caviar. Iran is also one of the world's biggest exporters of pistachio nuts.

paragraphs: Iran has factories that produce industrial products. Iran is also involved in the field of biomedical sciences.

paragraphs: About 90% of Iranian people are Muslim. The state religion is Shia Islam. It has been the state religion since the Safavid dynasty in the 16th century. This is the religion of about 75% of Iranians. They belong to the Twelver branch. About 9% of Iranians Muslim belong to the Sunni branch of Islam. The 9% of Iranians who are not Muslim are Bahá'ís, Mandeans, Zoroastrians, Christians and Jews. It is thought that there are between 300,000 and 350,000 Persian (Iranian) Jews.


title: Gautama Buddha

paragraphs: The Buddha is a titled used to refer to a man named "Siddharth Gautama". It means Fully Awakened One. He was born in a region of what is now known as Nepal and was the person who created the religion of Buddhism. He lived from about 563 BC to about 483 BC.

paragraphs: He is also called Shakyamuni Buddha because he was a

paragraphs: member of the Śākyan clan, the ruling class of an aristocratic republic in that region.

paragraphs: About 2600 years ago, a clan called the "Shakyas" ruled the city of Kapilavastu.

paragraphs: Siddhartha Gautama was born just outside the city in Lumbini. His father was a ruler named Shuddhodana, and his mother was named Maya. Maya died when Siddhartha was about 7 days old. His father controlled him in a very peaceful and nice way. There were home tutors for him as he was not interested in the outward things that took place at that time. Siddhartha lived in luxury; his father kept trouble and hard work far from him. A seer predicted that if Siddhartha stayed inside his palace his whole life, then he would become a great king. However, if he left the palace, then he would become a great religious leader. The king did not want his son to become a religious leader. He kept Siddhartha in the palace for his entire childhood.

paragraphs: When Siddhartha turned 16 years old, his father found a woman for him to marry. He married a woman named Yashodhara, and they had a son named Rahula. Although Siddhartha had everything he could want, he was still not happy. He wanted to learn about life outside his palace.

paragraphs: Legend says that he got out of the castle against his father's orders. He saw the ""Four Great Sights"": an old man, a sick man, a dead man, and a holy man with no home.

paragraphs: Siddhartha left his family, his land and everything else at the age of 29. He left everything to be a mendicant (a wandering ascetic); eventually he became a religious leader for the people.

paragraphs: Many holy men at this time were "ascetics". They hurt their bodies for religious reasons. They abstain from certain pleasures so they can get rid of desire. One group of ascetics were called the Jains. They practiced self-denial and made themselves suffer very much. They believed this would free the ātman (soul) from pain and sadness. There were many types of ascetic mendicants (wanderers) throughout the region which would become known as India.

paragraphs: Siddhartha tried these ascetic practices and meditation techniques, and eventually became better than his teachers. He still found no answer, so he left his teachers and friends to discover another way. He decided to eat only six grains of rice a day. He tried holding his breath. His body became very thin, like skin and bones, and he nearly died. Still, he had no answer.

paragraphs: Siddhartha began to think again about this path. He recalled sitting under a roseapple tree as a boy, and reaching a profound happy peaceful state. He thought this memory might point to a better way than hurting himself. He accepted a meal of milk-rice so he would have strength to make focussed effort. He found a fig tree (now called the "Bodhi tree") and decided to meditate beneath it. He promised himself that he would not leave this spot until he had found "enlightenment". He meditated under the tree (some say for 49 days). His mind is said to have become pure, and then--after a total of six years practicing--he became enlightened. He was now the Buddha the Fully Awakened One.

paragraphs: When the Buddha became "enlightened", he found the answer to "suffering", and he knew how to defeat "suffering". This answer was called the Four Noble Truths. He was not sure if he should teach his new ideas or not. He asked himself if the world was ready for such a deep teaching. But in the end, he decided to travel to a town called Sarnath to teach the people his new way. He taught about the Four Noble Truths and the Noble Eightfold Path. The people listened to him.

paragraphs: When he taught, he did not pretend to be a god. He said he was just a man who had found the meaning of life (enlightenment), and that any person can also find the meaning of life. For the rest of his life, he walked all over Southern Nepal and parts of India to teach people what he believed. He started a "Sangha", which is a group of Buddhist monks and nuns. Many people became enlightened because of him. At the age of 80, after 45 years teaching the Four Noble Truths, Gautama Buddha died.

paragraphs: The teachings of the Buddha are known as "Buddhism". Buddhism is mostly about ending the feeling of pain that all people feel inside. Gautama Buddha taught that old age, sickness, death and suffering is a part of everyone's life. He taught that pain is caused by craving. And he showed that there is a way to end craving and end suffering by doing good things, not doing bad things, and training one's mind. When a person is able to perfect these qualities, they will gain "enlightenment".

paragraphs: Buddhism teaches non-harm and balance – not going too far one way or the other. The Buddha taught people to meditate while sitting in the lotus position or when standing, sitting, walking, or lying down. The Buddha urged his followers to remember the Teachings, and ask questions. Some Buddhists chant (which was a way to remember and preserve the Teachings). Buddhists sometimes do these things to understand the human heart and mind. Sometimes they do these things to understand the way the world works. Sometimes they do these things to find peace.

paragraphs: The Buddha taught that people should not look to gods to save them or bring them enlightenment. The gods may have power over world events and they might help people, or they might not. But Buddha believed that it is up to each person to become enlightened.


title: North

paragraphs: North is one of the 4 main directions on a compass. North is usually up on most maps. For Example: The United States is north of the Mexico, which is itself north of Brazil. The North Pole is the farthest north you can go. The North of the world is considered to be the top.


title: Epiphany (software)

paragraphs: Epiphany is a Web browser for GNOME. It is also available for Mac OS X and was made from Galeon.

paragraphs: It uses the Gecko layout engine from the Mozilla project to show web pages; however, the Epiphany developers have a new but less stable version of Epiphany 2.21.4 using the WebKit engine instead of Gecko. The Epiphany team wants to stop using Gecko and only use the WebKit engine, by the time they release Epiphany 2.24 or 2.26. Epiphany has tabbed browsing, cookie management, popup blocking and an extensions system. Epiphany can be extended with the Epiphany-extensions package in GNU/Linux Operating Systems.

paragraphs: Epiphany was made from Galeon by Marco Pesenti Gritti (also the creator of Galeon) with the aim of making a web browser with a very simple user experience. Because of that, Epiphany does not have its own themes, instead, it uses GNOME’s settings that are set in the GNOME Control Center.


title: Video game console

paragraphs: A video game console is a machine that is used to play video games. Video game consoles usually connect to a television.

paragraphs: Special controllers are attached to the console to control the game. Some video game consoles are handheld. They can be carried around and have their own screens. The Nintendo DS and PlayStation Portable are examples of handheld consoles. Some video game consoles can also run general software, such as Linux.


title: PlayStation

paragraphs: The PlayStation (often known as the PS1 or the PSX) is a video game console made by Sony. At the time, it was competing against the Nintendo 64 and the Sega Saturn. PlayStation games were stored on CDs. The controllers that were first released with the console had no analog joysticks on them, but analog joysticks and a vibration feature were added to later controllers. A slimmer version of the console called the PSOne was released in 2000. It was white instead of grey.

paragraphs: The PlayStation and the PSOne have sold over 120 million consoles.

paragraphs: The PocketStation was a very small games console released as a peripheral (an extra accessory) for the PlayStation. It had a clock, an LCD display and four buttons. It could be used as a memory card. It wasn't released in the United States, because it did not sell well.


title: Election

paragraphs: An election is a way people can choose their candidate or their preferences in a representative democracy or other form of government.

paragraphs: Most democratic countries hold new elections for their national legislature every few years. What elections do is select representatives for the local areas. These are called MPs (Members of Parliament) in the British parliamentary system. Parliamentary systems may have a head of government and a head of state, but sometimes the two posts are held by the same person.

paragraphs: The legislature chooses the government, usually by majority vote in the legislature. Some democracies elect a president, who then selects the government. Many democratic countries also have regional, provincial or state elections.

paragraphs: There are different ways to organize an election in different countries. Voters might vote for an individual, or they might vote for a political party (party list). This is because different countries use different voting systems.

paragraphs: Countries that are not democracies can also hold elections. This is usually done to let the people choose a local representative (like a mayor). Also many countries call themselves democracies, but behind the scenes have a more autocratic form of government.

paragraphs: Elections keep a democratic country functioning, as they give people the right to select their own government. However, there are ways a government can "fix" elections. Opposition candidates are permitted in former USSR countries, but they are usually prevented from using broadcasting or the newspapers. This means that, in effect, the ruling president is never challenged. Elections which are fixed are sometimes called sham elections or show elections.


title: Medicine

paragraphs: Medicine is the science that deals with diseases (illnesses) in humans and animals, the best ways to prevent diseases, and the best ways to return to a healthy condition.

paragraphs: People who practice "medicine" are most often called medical doctors or physicians. Often doctors work closely with nurses and many other types of health care professionals.

paragraphs: Many doctors specialize in one kind of medical work. For example, pediatrics is the medical specialty about the health of children.

paragraphs: In this specialty, the doctor is trained to provide anaesthesia and sedation. This is important for surgeries and certain medical procedures. Anaesthesiologists also provide pre-operative assessments, ensuring the patient is safe during the operation and successfully awakens from anaesthesia after the operation. They assess for medical conditions and suitability for anaesthesia. They screen for risk factors prior to surgery and try to optimize the operative environment for the patient and the surgeon. They are the doctors who give epidurals during labor and delivery, provide spinal blocks, local nerve blocks, and general anaesthesia for procedures. They are the doctors who are especially trained in intubation (putting a tube into the lungs to help a person artificially breathe when the person is paralyzed and asleep during surgery). Hence, due to their skill in intubation, they are often the first line responders for emergencies. They help people who are in distress with their breathing, who have lost their airway or when their airway has become obstructed.

paragraphs: A cardiologist is a doctor with special training on the heart. The doctor in this field ensures the heart is healthy and functions properly. The heart is a vital organ whose role is to pump blood to the rest of the body. The purpose of blood is to deliver oxygen to the tissues. Without the heart functioning well, our tissues and organs would die and not function properly. Cardiologists treat heart attacks, sudden cardiac arrests, arrhythmias (rhythm issues related to a faulty electrical system of the heart), heart failure (where the heart fails to pump blood forward properly) and many other heart related illnesses. They specialize in life saving procedures like cardiac stents and cardiac ablation. There is a subspecialty within cardiology called "Interventional cardiology." These are cardiologists who specialize in interventions or procedures to save the function of the heart, such as cardiac stenting or angiography.

paragraphs: This specialty consists of well trained doctors who practice cardiac surgery. They are best known for their role in cardiac bypass surgeries. In cardiac bypass, the surgeon restores blood flow to the area of the heart that was deficient due to a blocked coronary artery. This is usually done by taking a vein, most commonly the saphenous vein from the leg, to create a pathway of blood flow to the heart region that needs it.

paragraphs: Emergency room doctors are in charge of sudden important or life-threatening emergencies. In addition to dealing with heart attacks, strokes, traumas, issues that require immediate medical attention or surgeries, they also deal with a wide range of other health conditions, such as mental health and drug overdoses. Their training is broad and diverse as anyone can walk through the door seeking help. They see patients of all ages and walks of life. However, unlike a general practitioner or family doctor, their immediate goal is to make sure the patient is stable and exclude any serious or life-threatening diseases or conditions.

paragraphs: A family doctor, otherwise known as general practitioner, is trained to provide medical service to people of all ages, demographics, and walks of life. Their training is diverse to deal with a variety of conditions including all non surgical specialties. They also follow the patient from birth to death and are trained to treat an individual as a whole, in the context of their social setting and also their family situation and mental health. Unlike specialists who mainly deal with problems of one organ or system, family doctors deal with all parts of the body and synthesize this information for the patient's general health. They provide a global perspective of the person's health in the patient's unique life situation. They are an individual's regular doctor who knows the patient in their social and family context. They can refer to specialists for issues that require more detailed or specialized treatments unavailable to them as an outpatient or beyond their expertise.

paragraphs: Gastroenterologists are doctors who specialize in the gastrointestinal (GI) tract and upper abdominal organs. The GI tract is consists of the esophagus all the way down to the anus. The upper abdominal organs include the liver, gallbladder, pancreas and spleen. In addition to dealing with medical conditions associated with these organs, doctors in this speciality also perform endoscopies. This is where a camera is placed to visualize the esophagus and stomach (upper endoscopy) or the colon (lower endoscopy or colonoscopy). Gastroenterologists that specialize in the liver is called a Hepatologist. They are responsible for treating patients with liver failure or cirrhosis. They also treat patients with viral Hepatitis (A,B,C) and many other forms of liver disease.

paragraphs: Doctors in this specialty are trained to recognize and treat a variety of different conditions involving the internal organs. They have wide knowledge in a number of specialties including, but not limited to: Respirology, Nephrology, Gastroenterology, Cardiology. Doctors who practice broadly in this field are known as General Internists (or General Internal Medicine doctors). Internists can go to receive further training beyond residency in a particular field. For example, Gastroenterologists are internists that have chosen to specialize in GI medicine. Internal medicine doctors are in charge of inpatient units when patients are admitted for a general reason. Unlike family doctors and emergency doctors, although their training is diverse and they have broad knowledge in many organ systems, they do not treat or manage children, babies, or pregnant women. (Those patients are instead cared for by Pediatricians and Obstetrics/gynecology, respectively.)

paragraphs: Doctors in this field, abbreviated OBGYN or Obs/Gyn, specialize in women's health covering conditions of the female reproductive organs, and pregnancy care and delivery. Some examples of gynecological issues they deal with include contraceptive medicine, fertility workup and treatments, prolapse and incontinence, sexual health, ovarian tumors/ cysts, gynecological oncology. They are also surgeons in their fields, capable of performing numerous gynecological surgeries. Doctors in this field also practice obstetrical medicine, specializing in maternal fetal care and deliveries, complications related to deliveries, assisted deliveries (such as vacuum and forceps deliveries) and Caesarian sections.

paragraphs: This medical specialty consists of well trained doctors who recognize and treat medical conditions associated with the eyes. Some common complaints they see include red eye, eye pain, visual changes and trauma. They deal with many eye diseases including conjunctivitis, iritis, blepharitis, hordeolum, chalazion, glaucoma, cataracts, macular degeneration, retinal detachments, papilloedema, central retinary artery occlusion. They are trained to perform surgery.

paragraphs: These are doctors with special training to treat the ears, nose and throat. These are the doctors who will very commonly remove an organ call the "tonsils" from a patient.

paragraphs: This medical area, commonly known as chest medicine or respiratory medicine, deals with the respiratory system. It usually involves patients who require intensive care including life support and mechanical ventilation. Doctors of this field usually are knowledgeable in diseases and conditions of the chest, such as pneumonia or asthma. Doctors in this field tend to perform minor procedures in surgery of the respiratory tract. Pulmonary specialists often practice critical care medicine. They also manage complicated chest infections.


title: Transport

paragraphs: Transport, or transportation, is moving people or things from one place to another place. Transport can be divided into "infrastructure", "vehicles" and "operations".

paragraphs: "Infrastructure" includes roads, railways, airports, canals and pipelines. The infrastructure is the network where things are carried. Infrastructure also includes airports, railway stations, bus stations and seaports (docks). Infrastructure is usually built by governments and paid for by taxes from the citizens of a country or region. Infrastructure such as roads and railways are designed by civil engineers and urban planners.

paragraphs: "Vehicles" or vessels travel on the infrastructure. Vehicles include cars, trucks, trains and airplanes. Vehicles are usually designed by mechanical engineers. Vessels include boats, ferries, and barges which travel on canals and use docks and seaports. In the same way that trains use train stations, airplanes use airports. In the same way that trains use railway lines (train tracks), airplanes use flight paths and then fly in the sky.

paragraphs: "Operations" control the system. Operations include traffic signals, railway signals and air traffic control. Operations also include the government policies (a policy is a plan of action to guide decisions and actions) and regulations (a set or group of laws and rules) used to control the system, such as tolls, fuel taxes, and traffic laws.

paragraphs: Transport and communication can be used instead of each other (someone could telephone a person rather than visit them). Transport traffic also needs communication. For example, air traffic control lets more airplanes fly. So, an increase of either transport or communication usually leads to an increase in the other one.

paragraphs: Transport uses a lot of energy. Most transport uses hydrocarbons (oil and gas). This can create pollution. Environmental regulations (laws) and low-pollution fuels (for example liquified natural gas) can reduce pollution. But as more vehicles are used, more pollution is created. Ethanol and biodiesel pollute less than petroleum.


title: Road

paragraphs: People have been making roads for a long time. Roman roads in Britain and the Inca road system are famous. Transport by boats on waterways was usually easier and faster than transport by road. In the industrial revolution, the railway was invented. A railway is a special type of road, using railway tracks. Roads are now usually made for wheeled vehicles, like cars, to travel on.

paragraphs: Road building and care is usually paid for by taxes. Some roads are toll roads, where people pay to use the road.


title: Hawaiian Islands

paragraphs: From west to east, Hawaii is made up of the following Hawaiian Islands:

paragraphs: The Hawaiian islands, plus former islands now below sea level (guyots), make up the Hawaiian–Emperor seamount chain.


title: Mauna Kea

paragraphs: Mauna Kea is a dormant volcano in the Hawaiian Islands. It is the highest point in Hawaii at 4,205 meters. If measured from top to bottom, below sea level, it is 10,200 meters high and would be the tallest mountain in the world. It is around 1,000,000 years old. Mauna Kea means 'white mountain' because in winter it often has snow at the summit.

paragraphs: Mauna Kea is an important site for astronomy. Many different countries or institutions have an observatory there, including the National Astronomical Observatory of Japan. The W. M. Keck Observatory with its 10-meter mirror is one of the most powerful in the world. Mauna Kea is an important site, especially for infrared astronomy, because of its height and clear skies.

paragraphs: High altitude is important because atmosphere causes an effect called seeing, which limits the quality of images by blurring them. At high altitude, there is less atmosphere between the observatories and space and this lessens the effect.


title: Mauna Loa

paragraphs: Mauna Loa is an active volcano in the Hawaiian Islands of the United States.

paragraphs: “Mauna Loa” is Hawaiian for “long mountain”.

paragraphs: The volcano is at least in volume and over 4 kilometers above sea level. Measured from its base on the ocean floor it reaches above 8 kilometers making it the tallest mountain on Earth, but not the highest. That distinction is reserved for Mount Everest.

paragraphs: Measured from sea level Mauna Loa is 4,169 meters high. It is also one of the largest volcanoes measuring 60 miles long and 30 miles wide.

paragraphs: The world's biggest volcano is named Mauna Loa in Hawaii. Mauna Loa is part of the five volcanoes on Hawaii's 'Big Island'. The most recent time this volcano erupted was in 1984. It erupted 33 times in the last 170 years. Like all the other Hawaiian volcanoes, Mauna Loa was created by the movement of the Pacific tectonic plate which moved over the Hawaii hotspot in the Earth's mantle. It is a shield volcano. The largest recent eruption from Mauna Loa left a lava trail 51 kilometres (32 miles) long.


title: Kilauea

paragraphs: Kilauea is an active volcano in the Hawaiian Islands. It is a shield volcano. The volcano is 1,277 meters high. Kilauea is a large lake of lava. The crater of Kilauea is named Pu'u'O'o. The first eruption of Kilauea is estimated as 300 to 600 thousand years ago. Its first recorded eruptions were in 1823. Its most recent eruption was March 3 2018. It is still erupting now. The Hawaiian name "Kilauea" means "spewing" or "much spreading". It refers to the constant flow of lava. Kilauea lies on the curve of volcanoes on the island of Hawaii that includes Mauna Loa and Kohala. The volcano of Kilauea is one of the youngest and also is said to be the home of an ancient volcano goddess Pele. The oldest dated rocks are said to be about 23,000 years old. It has its own magma plumbing under the Earth that goes down under the Earths crust by 60 km. Kilauea has a basalt-based lava rock type. Kilauea was formed on a volcanic hot-spot.

paragraphs: In May 2018, the volcano erupted causing damage in nearby homes and streets.


title: Van

paragraphs: A van is a type of vehicle. A van can carry either goods or people. A van is usually bigger than the regular sized car. Panel vans (= vans whose cargo space has no side windows) are used for deliveries and carrying goods. These usually have large cargo space and few windows. A van which is used to carry people is often called a "minibus". It can usually carry many people, sometimes up to a total of 15.

paragraphs: Many companies make vans, including: Chevrolet, Daihatsu, Dodge, Fiat, Ford, GMC, Honda, Hyundai, Isuzu, Mazda, Mercedes-Benz, Mitsubishi, Nissan, Subaru, Suzuki, Toyota, Vauxhall, and Volkswagen.

paragraphs: A minivan is smaller and usually carries up to seven people.

paragraphs: You may usually drive a van with the same driver's license as an ordinary car, but the heaviest and largest vans may require a truck licence.

paragraphs: The demand for minivans is dwindling due to the introduction of crossovers. However, some companies still make minivans. The most popular minivans are the Toyota Sienna and Honda Odyssey.


title: Luggage

paragraphs: People use luggage to carry their possessions when travelling. In the United States luggage is often called baggage.


title: Pantograph

paragraphs: A pantograph is an machine. It is used in drawing or planning. It makes it easy to copy diagrams.

paragraphs: The device that an electric train uses to get its electricity is also called a pantograph, because it looks a bit like the drawing instrument.


title: Paperback

paragraphs: A paperback is a type of book. It has a cover of thick paper or thin cardboard. Paperback book covers can bend and be folded. The covers are laminated (have layers), and some of the methods are more durable (lasting) than others. Another name for paperback is "soft cover".

paragraphs: Paperback books may be glued or held by sewing. If the pages are held only by adhesive, the book will eventually come apart. The quality of the paper also varies. It is generally less white than bound hardback books because it is less bleached.

paragraphs: Usually, paperback books cost less money than hardback books. In the middle 20th century a "mass market" type of paperback became commonplace, having a standard size, fitting a standard display rack, and glued.


title: Palette

paragraphs: A palette is used for mixing colours.They are usually made out of plastic or wood but can be made out of other materials. An artist often uses one of these and is in fact an essential item in art, when painting.


title: Glow-worm

paragraphs: Other names for glow-worms are fire-fly and lightning bug.

paragraphs: There are several insects given this name. Most are beetles, but one is a fly, "Arachnocampa". They are nocturnal, active during the night. They have special organs that can produce light. This is used to find mates. The patterns in which the beetles flash is unique to each species.


title: Palette knife

paragraphs: A palette knife is not actually a knife. It has a very flexible steel blade and no sharpened cutting edge. It is a tool.

paragraphs: A palette knife is used for mixing paint colors. It may be used for mixing and applying a whole range of semi-fluid mixtures.


title: Foolscap

paragraphs: Foolscap is paper cut to the size of , sometimes . This was a traditional paper size used in Europe and the British Commonwealth, before the adoption of the international standard A4 paper, the most common standard size in the world. Foolscap was so called because, in the 18th century, folio-sized paper had the watermark of a fool's cap on it. Basically, it is taller than A4.

paragraphs: In North America, foolscap is lined, legal-size paper. In some South American countries it is called "oficio", because it is or was used for official documents.

paragraphs: Paper of the size is now very rarely used, being superseded by A4 (297 x 210). However, some ring binders, lever arch files, suspended files, and other filing related things still use the size.


title: Polymer

paragraphs: A polymer is a molecule, made from joining together many small molecules called monomers. The word "polymer" can be broken down into "poly" (meaning "many" in Greek) and "mer" (meaning "unit"). This shows how the chemical composition of a polymer consists of many smaller units (monomers) bonded together into a larger molecule. A chemical reaction bonding monomers together to make a polymer is called polymerization.

paragraphs: Some polymers are natural and made by organisms. Proteins have polypeptide molecules, which are natural polymers made from various amino acid monomer units. Nucleic acids are huge natural polymers made up of millions of nucleotide units. Cellulose and starch (two types of carbohydrate) are also natural polymers made up of glucopyranose monomer bonded together in different ways. Rubber is a mixture of polymers. Plastics are man-made polymers. Many fibers are made of polymers.

paragraphs: If the "units" called monomers in a polymer are all the same, then the polymer is called a "homopolymer". Homopolymers are named by adding the prefix poly- before the monomer name from which the polymer is made. For example, a polymer made by bonding styrene monomer molecules together is called polystyrene.

paragraphs: If the monomers are not all the same, the polymer is called a "copolymer" or a "heteropolymer".

paragraphs: Many polymer molecules are like "chains" where the monomer units are the links. Polymer molecules can be straight-chain, have "branching" from the main chain, or "cross-linking" between chains. As an example of cross-linking, sulfhydryl (-S-H) groups in two cysteine amino acid units in polypeptide chains can bond together to make a disulfide bridge (-S-S-) joining the chains together.


title: Phrase

paragraphs: A "phrase" is a group of words that adds meaning to a sentence. A phrase is not a sentence because it is not a complete idea with a subject, verb and a predicate.

paragraphs: In English there are five different kinds of phrases, one for each of the main parts of speech. In a phrase, the main word, or the word that is what the phrase is about, is called the "head." In these examples, it is printed in "bold". The other words in the phrase do the work of changing or "modifying" the head.

paragraphs: In a 'Noun phrase', one or more words work together to give more information about a noun.

paragraphs: In an Adjective phrase, one or more words work together to give more information about an adjective.

paragraphs: In a Verb phrase, one or more words work together to give more meaning to a verb. In English, the verb phrase is very complex, but a good description of its many forms can be found here.

paragraphs: In an Adverb phrase, one or more words work together to give more information about an adverb.

paragraphs: In a Prepositional phrase, one or more words work together to give information about time, location, or possession, or condition. The preposition always appears at the front of the phrase (preposition = pre-position).


title: Preposition

paragraphs: Prepositions are boring words made up by teachers to give their students something to do wile they relax

paragraphs: Prepositions often describe the position of something, the time when something happens or the way in which something is done. The prepositions "of", "to" and "for" have other functions.

paragraphs: Prepositions may sometimes be used to end sentences. For example, "What did you put that there for?" (better English is the alternative: "Why did you put that there?") Example 2: "A pen is a device to write with" (better English is "A pen is a writing device"). In general, because they are links, prepositions belong in the middle of sentences, rather than at the end.

paragraphs: The table below shows some examples of how prepositions are used in sentences.


title: Pronoun

paragraphs: A pronoun is traditionally a part of speech in grammar, but many modern linguists call it a type of noun. In English, pronouns are words such as "me, she, his, them, herself, each other, it, what".

paragraphs: Pronouns are often used to take the place of a noun, to avoid repeating the noun. For example, instead of saying

paragraphs: When a pronoun replaces a noun, the noun is called the antecedent. For example, in the sentence: "The dog that was walking down the street", the relative pronoun is the word that referring back to the antecedent, the word 'dog'. In the sentence "The spy who loved me", the relative pronoun is the word 'who' and its antecedent is the word 'spy'.

paragraphs: Pronouns are different from common nouns because pronouns normally do not come after "article"s or other "determiner"s. For example, people do not say "the it". Pronouns rarely come after adjectives. They are also different because many of them change depending on how they are used. For example, "we" is a 'subject' in grammar, but the word changes to "us" when used as an object.

paragraphs: Pronouns are the same as nouns because they both change for number (singular & plural), case (subject, object, possessive, etc.), and gender (male, female, animate, inanimate, etc.) Nouns and pronouns can be used in almost all the same places in sentences, and they name the same kinds of things: people, objects, etc. Even though they can not normally come after determiners, or adjectives, neither can proper nouns.

paragraphs: There are four kinds of pronouns: personal, reciprocal, interrogative, and relative.

paragraphs: This table shows all the personal pronouns in English that are commonly used today.

paragraphs: A subject pronoun can replace a noun that is the subject of a sentence. Refer to the table above; the subject pronouns are: I, You, He, She, It, We, They. An object pronoun can replace a noun that is the object of a sentence. A possessive pronoun shows who or what a noun belongs to.

paragraphs: Another type of personal pronoun is called the 'reflexive pronoun'. Reflexive pronouns are the words ending in '-self' or '-selves', such as: "myself, itself, themselves".

paragraphs: "It" and its other forms "its", and "itself" only refer to objects, not people. "They" and its other forms "them", "their", and "theirs" can be used as a singular, for a person who could be either male or female. For example: "The patient will be told how much "they" will be required to pay."


title: Adverb

paragraphs: An adverb is a word used to tell more about a verb, and it almost always answers the questions "how?", "when?", "where?", "how often?", and "in what way?". Words like "slowly", "loudly", "carefully", "quickly", "quietly" or "sadly" are all adverbs. Adverbs usually, but not always, end in "-ly".

paragraphs: Examples of adverbs in a sentence (with the adverb in italics): that is a weird word and is seen differently

paragraphs: An adverb can also modify (describe) an adjective or another adverb

paragraphs: In the first two examples the word 'well' is an adverb. In the last example, it is an adjective. This is one example in which the same word can be both an adjective and an adverb but not in the same sentence.

paragraphs: As a rule, the same word can play different roles but not in the same sentence. It all depends on what the word is doing in the sentence. It could be a noun, an adjective, an adverb, a verb, etc. Example: take the word 'cool'. In the sentence, "he walks cool", the word 'cool' is an adverb. In the sentence, "cool the hot dish", the word 'cool' is a verb. In the sentence, "it is a cool evening", the word 'cool' is an adjective. In the first example, "he walks cool", the word 'cool' really means 'coolly' as in "play it cool" (do not get excited; be calm).

paragraphs: Most adverbs are formed by adding ly to the end of an adjective. To see 100 adjectives used in Basic English, click here ---> : adjective


title: Sunday

paragraphs: Sunday is one of the seven days of the week. It is part of the weekend, along with Saturday. Sunday is the Sabbath or day of worship for most Christians (for example, Easter is celebrated on Sunday). Sunday is the beginning of the week in the United States, but is the end of the week in the United Kingdom.


title: Ottawa

paragraphs: Ottawa is the capital of Canada and is part of the province of Ontario. It is south of the Ottawa River. In 2004, there were about 808,391 people in the city. The region has about 1,146,790 people. The mayor of the city today (since December 2010) is Jim Watson. Ottawa is in the Ottawa Valley on the border with the province of Quebec. Ottawa is the fourth largest city in Canada.

paragraphs: When people talk about Ottawa, they are sometimes using the name as an eponym meaning the highest government in Canada, and not its local government or the city.

paragraphs: The cities of Ottawa, Kanata, Nepean, Gloucester and Vanier and the villages of Manotick and Rockcliffe Park joined in the year 2000 to form the new city of Ottawa. Ottawa also includes Orléans, which joined at that same time.

paragraphs: The city began with the name Bytown and became the city of Ottawa in 1855. The Rideau Canal ends in Ottawa.

paragraphs: Ottawa has many museums, many buildings for the government of Canada and many parks. There is a market area downtown.

paragraphs: There are many festivals during the year including Winterlude in February, The Tulip Festival in May, and BluesFest in the summer. There is also a large celebration on July 1st for Canada Day.

paragraphs: The Ottawa Senators play ice hockey in an arena called The Canadian Tire Centre.

paragraphs: The average yearly precipitation in Ottawa is 943 millimetres.

paragraphs: 2017 was a record year in Ottawa because there was precipitation of 1,213 millimetres during the first ten months of the year. The old record was in 1972, when the precipitation was 1,174 millimetres.


title: News agency

paragraphs: A news agency is a kind of company. It supplies information to newspapers, radio and television.

paragraphs: In the United Kingdom and some other countries a news agency or newsagent is a shop which sells newspapers, magazines and cigarettes.


title: Mudguard

paragraphs: A mudguard, fender or wing is a part covering the wheels of a vehicle to stop it from throwing off mud, water or objects from the road. It protects people and property from dirtiness, dampness, and damage.


title: Para rubber tree

paragraphs: A Para rubber tree (or simply, rubber tree) is the tree which naturally produces rubber. It is native to tropical areas from South America, in the Amazon (Brazil), but was spread by European farmers to the Far East.

paragraphs: Para Rubber trees belong to the Euphorbiaceae family. In the wild they may reach heights of 100 to 125 ft (30-38 m) with large cylindrical trunks with or without buttresses. Crop trees reach a width of about 20 in. (50 cm), usually with a short bole, and with a sloped taper.

paragraphs: Most rubber plantations are in South Asia and Southeast Asia. When trees reach 5-6 years old, they are harvested. Their trunks are cut just deep enough to tap the vessels without harming the tree's growth, and the sap is collected in small buckets. This process is known as rubber tapping. Older trees produce more latex, but they stop producing it after 30-40 years.


title: Safety curtain

paragraphs: A safety curtain is a curtain in theatre at the front of the stage. It is made of material that will not burn. The safety curtain may be lowered during the intermission and after the performance. A safety curtain is there in case there is a fire on stage. It will stop the fire from spreading to the auditorium where the audience sits.


title: Safety lamp

paragraphs: A safety lamp is a miner's lamp with a covered flame that used to be used in coal mines.

paragraphs: The first safety lamp was invented by William Reid Clanny. It used bellows and water to separate gasses. Later, two newer designs were invented. One newer design was the Geordie lamp, made by George Stephenson, and the other was the Davy lamp, made by Sir Humphry Davy. In 1815, Davy discovered that if a flame was in a lamp, it would not ignite the flammable gases in mines.

paragraphs: Coal mines are dangerous because of flammable gasses like methane that can accumulate (gather together). A lamp with a naked (exposed) flame might make these flammable gasses catch fire, causing an explosion, which could kill people. The safety lamp prevents the hot flame of the lamp touching the flammable gasses, reducing the chance of an explosion.


title: Christmas stocking

paragraphs: A Christmas stocking is a long sock hung by a fireplace or bed on Christmas Eve. Christmas presents are put into it for children. And it came from an old legend, which have now turned into a European tradition.


title: Sex

paragraphs: Sex is a type of reproduction common among living things. Sex is used by plants and animals, and also by fungi and various single-celled organisms. It usually needs two individuals which are different sexes from the same species. It works by combining genes from more than one source.

paragraphs: Organisms may have more than one kind of reproduction:

paragraphs: Asexual reproduction is easier than sexual reproduction, but there are benefits and drawbacks to both:

paragraphs: In humans, sex is normally either male or female. For example: John's sex is male. Jane's sex is female. Most of the time, the sex of a person depends on what sex chromosomes that person got from his or her parents. A woman's ovum (egg cell) contains one X chromosome. A man's sperm contains either an X or a Y chromosome. When a sperm and ova combine to form a fertilised egg, the baby may get either of these chromosomes from its father. If the baby gets two X chromosomes, it will develop into a female. If the baby gets one X and one Y, it will develop into a male. Before babies are born, their sex parts are already formed, but not ready yet. During Puberty, the sex parts finish developing as well as other parts of the body like breasts and body hair.

paragraphs: There are some exceptions to this rule. Sometimes, the process of meiosis, which makes the sex cells, can go differently. This can result in a person having 3 X chromosomes, or 2 Y chromosomes or XXY instead of XY. Other times, the body may not follow exactly what their chromosomes are telling it to do.

paragraphs: Some people may have sexual feelings that are different from their bodies. For instance, a male person may only be attracted to other males and not to females. This is called Homosexuality. There are also people, who feel they're a different sex from their bodies. These people are called Transgender. All these variations are sometimes called gender.

paragraphs: Sexual reproduction first appeared about a billion years ago. It evolved within single-celled eukaryotes. The scientific community still discusses why it appeared, and why it still exists. Reasons commonly given include:

paragraphs: Sexual reproduction is a process that can only be found in eukaryotes. These cells have a nucleus and mitochondria. There are other kinds of organisms (other than animals, plants and fungi), the other eukaryotes – such as the malaria parasite – that also engage in sexual reproduction. Some bacteria use conjugation to transfer genetic material between bacteria. This is not the same as sexual reproduction, but it results in a similar mixture of genetic traits.

paragraphs: In sexual reproduction the cells used for reproduction, called gametes, are either eggs or sperms. Fertilisation needs two different such cells. The mechanism of cell division only works when one sperm alone enters the egg. Once it is in, a fast reaction goes through the egg cell wall to shut off all other sperm.

paragraphs: Sex determination in biology is about the function of sex, not what individuals look like. In humans, males and females usually look different. In many species they do not, except for the sex organs.

paragraphs: Sex can be determined in different ways:

paragraphs: When there is sex determination there are basically two cases:

paragraphs: Usually, sex is determined by an organism's genes. With genetic sex determination, most alleles or genes that influence sexual development are on the same chromosome. That chromosome is then called the sex chromosome. Because genetic sex determination is controlled by a pair of sex chromosomes (or if of one of the chromosomes is there or not), there are usually the same number of male and female offspring. In humans, for instance, sperms carry either an X or a Y chromosome, and they occur in roughly equal numbers.

paragraphs: For some species sex is not determined by inheritance, but instead by environmental factors experienced during development or later in life. Many reptiles have temperature-dependent sex determination: the temperature embryos experience during their development determines the sex of the organism. In some turtles, for example, males are produced at lower incubation temperatures than females; this difference in critical temperatures can be as little as 1-2 °C.

paragraphs: Some fish change sex over the course of their life. This phenomenon is called "sequential hermaphroditism". In clownfish, smaller fish are male, and the dominant and largest fish in a group becomes female. In many wrasse the opposite is true—most fish are female at birth and become male when they reach a certain size. Sequential hermaphrodites may produce both types of gametes over the course of their lifetime, but at any given point they are either female or male.

paragraphs: In some ferns the default sex is hermaphrodite. Ferns which grow in soil which has previously supported hermaphrodites are influenced by hormones remaining to develop as male.


title: Hacksaw

paragraphs: A hacksaw is a tool for sawing. A hacksaw is designed for cutting materials like very thin metals and plastic. It has a handle on one end, and can be either pushed or pulled across the object being cut. There are manual and electric hacksaws.


title: Spade

paragraphs: In gardening, a spade is a tool for digging. It is similar to a shovel. It has a straight handle. For some purposes the difference between a spade and a shovel is important. It is hard to move gravel with a spade but a proper shovel can do it.

paragraphs: In games, a spade is one of the four shapes or "suits" on playing cards.


title: Hoe

paragraphs: A hoe is a tool in farming and gardening. It has a blade, usually metal, attached to a long handle, usually wood. There are many types of blade and several uses, probably the most common of which is weeding. Other uses include shaping the soil and harvesting root crops such as potatoes. Along with the spade and fork, the hoe is considered a basic, essential hand farming implement.


title: Shovel

paragraphs: A shovel is a tool used for moving loose material. Shovels have a flat bottom head which is angled slightly from the handle to enable scooping and moving of material.

paragraphs: Although a shovel can be used for digging, it is much less efficient than a spade. Spades are straight, and transmit force straight downwards. Shovels move loose material, such as coal, snow, gravel etc. They are usually made of metal at the bottom, and wood is sometimes used for the handle.


title: Plunger

paragraphs: A plunger is a tool. It is used to get rid of things that are blocking pipes. The plunger is placed over one end of the pipe, and the handle is pushed up and down. Doing this creates a sucking force, which makes the thing blocking the pipe move and unclog.


title: Ladder

paragraphs: A ladder is a tool which is made for people to climb up or down. Ladders have two vertical supports that go along the whole length of the ladder. Between these supports are the horizontal rungs. The rung is what the climber can put his foot on. The climber can use his hands to hold on to the rungs above him, or to the supports at the side.

paragraphs: Ladders can be made of metal, wood or even rope. There are different types of ladders.

paragraphs: Some ladders are made in one piece. They can be carried around and made to lean against something such as the wall of a house. There should be a good distance between the bottom of the ladder and the wall so that the ladder is not too vertical, otherwise the ladder might fall backwards and the climber would fall off. Sometimes these ladders are extension ladders. Extension ladders are made in two or more sections so that the ladder can fold up to make it easier to carry about and to store. To open up the ladder, each section slides up almost to the top of the next section.

paragraphs: Step ladders are useful in the home or the garden to reach things that are not too high, e.g. ceilings or the tops of hedges. They have two parts which are joined together by a hinge, so that they are shaped like an upside down V. There is usually a platform at the top to stand on, but this can be dangerous unless great care is taken that the ladder will not wobble or fall down.

paragraphs: Some ladders are vertical (they go straight up or down). These are fixed onto something. Examples are: ladders in a swimming pool for climbing in and out of the water, small ladders to climb up to a top bunk bed, ladders at the side of a big boat or at the side of a canal lock or of any other high or low construction where workmen may need to get up or down to do repairs.

paragraphs: Fire engines always have ladders. They often have a turntable ladder which makes it possible for the ladder to be facing in any direction.

paragraphs: Rope ladders can be folded away easily. They may be used for climbing trees or for rock climbing or in caves.


title: Oral history

paragraphs: Oral history is history that is told rather than written down. It is given through talking rather than reading a book. It is usually passed from generation to generation in order to explain events that have occurred.

paragraphs: Though today oral history is not as popular as written history, it is still used in many places as a way of transferring knowledge about the past.


title: Generation

paragraphs: A generation is used to mean the average amount of time between the birth of parents and the birth of their children. It is also used to mean all the people on one level of a family tree. For example, your brothers, sisters and cousins are in the same generation as you. It can also be used to mean a series of something, like a generation of a car model (2nd generation, etc.).


title: Gene

paragraphs: Genes are forms of DNA. DNA is a collection of chemical information that carries the instructions for making the proteins a cell will need. Each gene contains a single set of instructions. These instructions usually code for a particular protein. Humans have about 20,000 genes that code proteins and many more that are non-coding. Half of a person's genes come from the mother. The other half come from the father.

paragraphs: Originally: a hereditary unit which occupies a specific position ("locus") on a chromosome. Other definitions are ways the gene showed itself:

paragraphs: Modern definitions must take note of later discoveries. There are now two classes of genes:

paragraphs: Genes are passed on from parent to child and are an important part of what decides how children look and act (their biological properties). Genes affect the way our bodies work, including how we look. Our eye, hair and skin color are decided by genes. It is said that genes cause "genetic" effects in our bodies.

paragraphs: A gene may be "dominant" or "recessive". These terms refer to the effect a gene has on the offspring who carry it in their genome.

paragraphs: For example, let's say a mother only has genes for brown hair and a father only has genes for red hair. The child will inherit – receive – genes for red hair (from her father) and brown hair (from her mother). The brown hair gene is 'dominant' to the red hair gene. This means the child will have brown hair even though she has genes for both red and brown hair. This means only one dominant gene is needed for the child to receive that particular trait, while two recessive genes are needed for one.

paragraphs: A recessive trait might stay hidden for many generations. Let us use the child from the last example. We will call her "Mary". Mary has brown hair but has genes for both red and brown hair. Let us say Mary grew up and married Tom. Tom also has brown hair, but like Mary one of his parents had red hair. This means Tom has genes for both red and brown hair. Mary and Tom would each have a chance of passing either brown or red hair genes to their children. This means that the children of Mary and Tom could have either red or brown hair. This explains why a person might look different from their parents, but look like their grandparents or great grandparents.

paragraphs: The structure of a gene has many elements: the actual protein coding sequence is only a small part. There are DNA regions that are not transcribed as well as untranslated regions of the RNA.


title: Alliteration

paragraphs: Alliteration is when a sentence or phrase has many words that start with the same sound. It is commonly used in advertising, poetry, headlines, and tongue-twisters. Basically the first consonant repeats itself throughout the sentence.

paragraphs: Alliteration is common for poetry. It was used one thousand years ago in Anglo-Saxon poems. A fine example is a strophe from "The Rime of the Ancient Mariner" by Samuel Taylor Coleridge:

paragraphs: Robert Browning used alliteration many times, too. he employed it in the poem "Summum bonum". This is a Latin expression and means "all the best".

paragraphs: Alliteration is most commonly used in modern music but is also seen in magazine article titles, advertisements, business names, comic strip or cartoon characters, common sayings, and a variety of other titles and expressions.

paragraphs: One example of alliteration is "Sally sold sea shells by the sea shore". In "Death Note", the pseudonym of the detective, L, is Ryuzaki Ryuga, his real name is L Lawliet.

paragraphs: Often, characters in books are named with alliteration. Many names in Harry Potter feature alliterations (for example, Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw, and Salazar Slytherin). Similarly, in "Hairspray", most characters' names feature alliterations (e.g. Tracy Turnblad, Link Larkin, Corny Collins, Dan Dougherty, Penny Pingleton, and Seaweed Stubbs).

paragraphs: Titles of books sometimes use alliteration, including the titles of all thirteen books (except the last one) in Lemony Snicket's A Series of Unfortunate Events. Author Jeff Lindsay's novels about serial killer Dexter Morgan all feature alliteration in their titles: for example, Darkly Dreaming Dexter. Another example is William Shakespeare's Love's Labour's Lost.

paragraphs: A common application of alliteration is in books intended for children learning about letters. Animalia by Graeme Base famously applies alliteration within a storybook, going in order through each letter of the English alphabet and providing many sentences with alliteration.

paragraphs: Places in books: Bat Barn, Terror Tombs, Vampire Village, etc.

paragraphs: Code names: The release names of the Linux distribution, Ubuntu (e.g. Breezy Badger, Hoary Hedgehog, Feisty Fawn, etc.).

paragraphs: Game Titles: Prince of Persia (also the tag: Prince of Persia – Warrior Within).

paragraphs: Companies company use this alliterative effect all the time. The major reason companies use this technique is to ensure that their brand name is memorable. Think, for example, of all of the famous and well known brands and companies that have used alliteration in their names:

paragraphs: Alliterative names can also help you stand out in the crowd and can make you more memorable. For example, both fictional characters and real people may stand out in your head as a result of the alliterative effect of their name. Think of:

paragraphs: •Katie Courec (Remember, alliterative words don’t even necessarily have to start with the same letter, they simply have to have the same first sound).

paragraphs: Finally, many famous phrases, quotes and saying also make use of alliteration:

paragraphs: Alliteration is commonly used since it adds interest to a sentence and can be a great way to help you remember names and phrases that you might other wide forget. Enjoy alliteration. It is a very fun and useful literary device.


title: Homophone

paragraphs: Homophones are words that sound the same as another word but have a different meaning, and often a different spelling.


title: Condensation

paragraphs: Condensation is the process through which gas changes into a liquid when it touches a cooler surface. Condensation is an important part of the water cycle. It is the opposite of evaporation.

paragraphs: Condensation of water is when water changes from gas to a liquid or crystal shape. Any gas can condense, either because the temperature is dropping or the pressure is increasing. In either case the pressure of the condensing gas is higher than the vapor pressure of the gas, at that temperature).

paragraphs: During condensation, the molecules in the matter slow down. Heat energy is taken away, causing the state of matter to change.

paragraphs: Condensation is exothermic. This means that condensation makes the temperature go up. Evaporation is the opposite and causes a temperature loss.

paragraphs: It is a useful process. One use is in distillation. The gas made from a boiling liquid mix is sent to a condenser, where the different parts condense differently. This can purify a liquid, such as alcohol or water. The condensing liquid makes heat, which must be removed for the condensation to continue.


title: Precipitation

paragraphs: Precipitation is a form of water from the atmosphere. It is a term in meteorology, and includes rain, snow, sleet, ice pellets dew, frost, and hail. These form by condensation from atmospheric water vapor, and fall under gravity.

paragraphs: Fog and mist are not precipitation but suspensions. In that case, the water vapor does not condense sufficiently to precipitate.

paragraphs: If liquid, precipitation can be measured using a rain gauge. The most common form of solid precipitation is snow. Snow is made when temperatures are so cold that water vapor changes directly to solid crystals. Frozen rain is hail or ice pellets.


title: Relative humidity

paragraphs: Relative humidity is a way of describing how much humidity is present in the air, compared to how much there could be. Meteorologists often use the relative humidity as a measurement to describe the weather at various places.

paragraphs: When the temperature is warm, more water vapor can be in the air than when it is cold. If the actual amount of vapor is compared to the total amount there could be as a fraction, then the number tells if the air feels dry or moist. The value is usually written in percent, where 0% means that the air is totally dry, and 100% means that it is so moist that mist or dew is about to form.

paragraphs: When the temperature is lowered to the dew point, relative humidity become 100% and the water vapor condenses, making precipitation as dew, rain or snow (etc.).