ejaasaari/simplewiki-2025-04-01 huggingface dataset:
Many animals develop in separate stages. A larva (plural: "larvae") develops from the egg in those animals. It is a separate life stage from the adult reproductive stage. A larva does not look like the adult animal, and changes shape (known as metamorphosis) as it grows up. There may be several larval stages before the adult form. Tadpoles, maggots and caterpillars are larvae. Marine organisms with a larval stage often release large numbers of eggs and sperms into the water column. After fertilisation, the eggs develop into tiny larvae. The larvae develop and grow for some time before metamorphosing into adults. Most marine invertebrates and many fish have a pelagic larval stage or pelagic eggs. These live in the plankton, and may be transported long distances. Evolutionary theory. Probably the most widely accepted theory explaining the evolution of larval stages is the need for "dispersal". Sessile organisms such as barnacles and tunicates, and sea-floor groups like mussels and crabs, need some way to move their young into new territory, since they cannot move long distances as adults. Many species have relatively long pelagic larval stages (how long a larva is in the water column). During this time, larvae feed and grow, and many species move through several stages of development. For example, most barnacles moult through six "nauplius" larva stages before moulting to a "cipris", when they look to settle. The larvae eat different food from the adults, and disperse. The other consideration is the small size of the eggs. If animals lay many small eggs (and most do), then the young stages cannot live the life the adults lead. They must live a separate life until they have the size and capability to live as an adult. This is what the larvae do. Origin of vertebrates. A long-standing theory is that in transformed larvae of sea-squirts (tunicates) lies the origin of vertebrates. Tunicates are sessile, but their larvae are mobile, and have some features found in early vertebrates. The process of paedomorph
Amphibians are members of the class Amphibia. The living ones are frogs (including toads), salamanders (including newts) and caecilians. They are four-legged vertebrates which are cold blooded. Amphibians lay their eggs in water, usually in a foam nest. After hatching they are tadpoles, which live in the water and have gills. The tadpoles change into adults in a process called metamorphosis. When they are adult, they have lungs to breathe instead of gills, and legs. Adult amphibians also use their skin to take in oxygen, and some species of salamanders do not have lungs. The earliest amphibians evolved in the Devonian from lobe-finned fish which had jointed leg-like fins with digits. They could crawl along the sea bottom. Some had developed primitive lungs to help them breathe air when the stagnant pools of the Devonian swamps were low in oxygen. They could also use their strong fins to hoist themselves out of the water and onto dry land if necessary. For tens of millions of years, during the Carboniferous and early Permian, amphibia were top predators on land, especially in the low-lying tropical river systems. In drier conditions, they were less effective, and the ancestors of mammals and reptiles (the Synapsids and Sauropsids) gradually took over the land. They laid cleidoic eggs, which had hard shells, and could be laid out of water. Most of the early large amphibians went extinct in the Triassic period; a few survived to the Lower Cretaceous. The only living amphibiana today are the Lissamphibia. These include the Anura (frogs and toads), Caudata (salamanders and newts) and Gymnophiona (caecilians). They are all rather small, compared with mammals or reptiles. The smallest frog and vertebrate in the world is the New Guinea frog ("Paedophryne amauensis"). The biggest amphibian is the Chinese giant salamander ("Andrias davidianus"). Amphibia are found everywhere in the world, except Antarctica, and
Gills are what fish, amphibians, and some other animals use to breathe in water. They have feathery parts which cause water to move across the animal's body, which contains dissolved oxygen, after the animal has swallowed the water. The oxygen is absorbed into the animal's blood, causing carbon dioxide to move out of the animal's blood and into the water through the gills. Fish and frog gills are hidden on the sides of their heads. Sharks have many gills slits on their necks. Baby salamanders have gills that stick out like leaves from their heads. In mushrooms, gills are the spore-bearing structure in agarics (gilled mushrooms) while fish and some young amphibians use them to get oxygen others breath. Some insects that live in water have a plastron, which is a kind of gill. It is a patch of special hairs that keeps the water away from the insect's spiracles. This allows them to continue to take in oxygen and remove carbon dioxide while they are under water.
Frogs are amphibians and vertebrates of the order Anura. There is not much difference between frogs and toads, and they are not classified separately. This is because the toad lifestyle, with its dry, rough, skin, is an adaptation to living in drier habitats. The toad form has evolved a number of times independently, an example of convergent evolution.  Frogs can live on land and in fresh water. They cannot survive in salt water. Their development is by metamorphosis. They usually hatch as tadpoles from eggs, which are laid by a female frog. The eggs are called frogspawn. Tadpoles have tails and gills. The next stage, the "froglet," develops lungs to breathe air instead of gills, but still have tails. The fully grown frog has long legs and no tail. Adult frogs can jump with their legs. They have long tongues that they use to catch bugs. They make a sound called a croak. Some species live in trees, and some types of frog are protected by being poisonous. Frogs live all over the world. If a foreign species of frogs is introduced to another country, the local ecosystem might be affected. Frog legs are sometimes eaten as food in France, China, and the Midwest of the United States. The killing of frogs might have an effect on the ecosystem. For example, frogs eat mosquitoes. If frogs are killed, then there are fewer frogs to eat mosquitoes, so more and more mosquitoes are born. Therefore, in these areas, there are more diseases that mosquitoes carry, because there are more mosquitoes. However, for this to apply, frogs would have to be a major predator of mosquitoes. This would only rarely be the case. Frogs are members of the class Lissamphibia, the only class of amphibians which has survived to the present day. Characteristics. Frogs are cold blooded animals. This means that they need heat to keep up their body temperature. If the temperature outside is cold, amphibians will not be active. Amphibians can get heat from the sun, usually indirectly: whereas reptiles can bask in the sun, amphibia usually do not, because
A chemical compound is a chemical formed from atoms of different chemical elements. The different atoms are joined by chemical bonds. Each compound has a fixed ratio between the elements. The elements stick together so strongly that the compound behaves like it is one substance. The chemical that is made depends upon what atoms it is made of and how they are joined together. Many compounds are made of separate molecules. Each molecule has the exact same number and types of atoms. For example, every water molecule has one oxygen atom and two hydrogen atoms. Other compounds are made of a large network of atoms. For example, sodium chloride always has equal numbers of sodium and chlorine atoms, but there are no separate molecules. Chemical compounds can be solids like sodium chloride, liquids like water, or gases like carbon dioxide. We get compounds from natural sources such as plants or make them in laboratories. Compounds can be made from others by scientists and these are called "synthetic chemicals". When different compounds are mixed together they may have a chemical reaction.  Some chemical compounds can be dangerous but are safe if they are used the right way. Most dangerous chemicals are only used by scientists who have had special training in how to handle and use them. These chemicals might be poisonous, corrosive, explosive, they may catch fire easily, or they may react with other substances. People who work in factories near chemicals often wear special clothes that stop the chemicals from hurting their body.
Wood is the main substance in trees. It is mainly formed by the xylem vessels which carry water up the plant. The two main substances in wood are cellulose and lignin. Wood is used to make buildings and furniture, and also for art. Firewood is a fuel. Paper is made from wood fibres. Wood is a renewable resource although it has become scarcer in recent centuries. Its origin is about 425 million years ago. Wood is hard to cut, but it is also strong. A lumberjack is a person who cuts down trees. After a tree falls, the wood in it can be cut into long, straight pieces called lumber. Lumber can then be used to make posts, or put together with nails, screws, or even glue to make wooden frames for other shapes. Wood comes in many different kinds. Oak, maple (hardwood) and pine and redwood (softwood) are widely used types of wood. Woods are usually divided into softwood (from conifers) and hardwood from flowering plants. Housing. For a long time and even today, many buildings, mostly houses, have been made of wood. To build a house with wood, lumber is put together into frames that are the shape of each wall, floor, and roof of the house. Then the frames are placed into the shape of a house. Then the frames can be covered to make solid walls. Sometimes the walls are made of more wood. When the outside of a house or building is covered in wood, the wooden pieces are usually flat and stacked. These pieces are called shingles. Wood is also sometimes used in other parts of the house, like doors and staircases. Wood is also used to make fences. Carpentry. Carpenters make houses of mostly soft wood such as pine. For many kinds of furniture they use harder wood such as maple or oak. When someone builds something with wood, they often paint it. Paint protects and beautifies the wood. Some people like the look of wood, so they put clear paint called "varnish" on it. This helps to protect the wood and gives it a shiny finish. Some people make art with wood. Sometimes sculptures are built with wood:
Chalk is a type of limestone. It was made by calcareous (CaCO3) skeletons of tiny planktonic algae called coccoliths. They live in the sea in huge numbers. They make chalk (CO2) as a by-product of their photosynthesis. The chalk cliffs of Dover and elsewhere were made when England was below the equator in a tropical sea. It was in the Upper Cretaceous, when the Earth was even warmer than now. There are coccoliths today, but not the same species as formed the white cliffs. Air and water do not wear chalk away easily, so when chalk is next to the sea, it often makes a large cliff. The "White Cliffs of Dover" in Kent, England are a good example of this. Chalk holds water, so these chalk hills may have a lot of water in them. When the weather is very dry, water comes slowly from the chalk.  Blackboard chalk is not real chalk. It is really gypsum (calcium sulfate), but people call it "chalk". People use it for drawing on hard things, because it is soft. If this chalk is rubbed on something hard or rough, it will leave a mark. People often write with chalk on a chalkboard or blackboard. A chalk eraser or water can be used to clean the chalk marks away so the board is clean again. Shops usually sell blackboard chalk in sticks that are about 5 cm long. There are also big pieces of soft chalk for children to write on the ground with, for example on concrete (such as a sidewalk) or on asphalt. It is usually okay to write on the ground with this kind of chalk, because the rain will wash the chalk away. Tailors' chalk is not real chalk either. It is talc (magnesium silicate). Tailors use it to draw on material when they are making clothes.
Utilitarianism is the view that the right thing to do is whatever is most useful. It is a about ethics. The word "utilitarianism" comes from the word "utility", which means "usefulness". In most forms of utilitarianism, things that increase human well-being or happiness are called useful. This is not limited to the happiness caused by a single action but also includes the happiness of all people involved and all future consequences. In general, the theory of utilitarianism is that whatever brings the most happiness to the greatest number of people is the right thing to do. History. The theory was made popular by 18th and 19th century British philosophers like Francis Hutcheson, Jeremy Bentham, and John Stuart Mill, but the idea goes all the way back to ancient times. Bentham wrote about this idea with the words "The greatest good for the greatest number," but did not use the word "utilitarianism". It was Mill, a follower of Bentham's ideas, who named the idea. Utilitarianism in Practice. Many philosophers argue that utilitarianism has important practical implications for how we should live ethically. For instance, according to utilitarianism we should help the poor, prevent animal suffering, and ensure that future generations have good lives.
A village is a place where people live, normally in the countryside. It is usually larger than a hamlet and smaller than a town or city. In some places, it may be a kind of local government. The dwellings in a village are clustered fairly near one another, not scattered broadly over the landscape. In the past, villages were where most people lived. Villages were a usual form of community for societies that do subsistence agriculture, and for some non-agricultural societies. After the industrial revolution, when people started making a lot of things in factories, people lived more in towns. Moving to towns is called urbanization. When villages grow a lot they can grow into towns and then cities. This is what happened to Dubai and Chicago. United Kingdom. In The U.K. the main difference between a hamlet and a village is that many villages have a church. Most villages are long-standing. The land has been settled (peopled) since the ice age. The soil is generally very fertile, and the land was once heavily forested. Much of what was forest was cut down to make ships, and farming replaced it. The land is fertile because of the deep loam (soil) in many places. That is partly due to the ice age, since the ice cover moved and ground against the bedrock. United States. Incorporated villages. The word "village" is not used in most states. However, in twenty US states, a "village" is a sort of local government, similar to a city but with less power and for a smaller place. But this is not so in all the United States. In many states, there are villages which are bigger than the smallest cities in the state. The difference is not the population, it is how much power the different sorts of places have, and what they do for people living there. New York. In the state of New York, a village is a place which is usually called a town.  Unincorporated villages. In many states, a "village" is only a place where people live, with no legal power, similar to a hamlet in New York state. The name for these is "unincorporated villages".
Chelmsford a city in the county of Essex, England. It is northeast of London, about halfway to Colchester. It is nearly in the centre of the county and it is the county town of Essex, but it is not the biggest or the oldest town in the county. It is the centre of the "borough" of Chelmsford, which is a bigger place than the city. Chelmsford has the smallest cathedral in England. John Dee, who wrote the English version of "Euclid", went to the Cathedral school in the sixteenth century. Chelmsford is also home to some of the Anglia Ruskin University campuses. People. The number of people living in the borough is about 170,000; about 115,000 of those live in the city. Transport. About 20,000 people from Chelmsford travel to London every weekday. Another 20,000 people work in Chelmsford who live outside the city. This makes Chelmsford the busiest "ordinary" railway station in England (not including junctions and terminuses). (The busiest of all is Clapham Junction railway station). The A12 road from London, which the Romans first built between London and Colchester, went through the town, but now goes around the east, so the number of cars in the town is smaller. Industry. Chelmsford has been an important centre for industry since the 19th century. It became home to the UK's first electrical engineering works (in 1878), and its first ball bearing factory (in 1898). In 1898, Guglielmo Marconi, the "father of radio" opened the World's first radio factory in Hall Street, with about 50 workers. In 1920 the factory was also the home of the first official sound (radio) broadcasts (radio people could listen to from a long way) in the United Kingdom. In 1922 the world's first "regular" radio broadcasts started at the Marconi Research Centre at Writtle near Chelmsford. Places of Interest. Places of interest in and near Chelmsford are for example Writ
Contract bridge, or just bridge, is a trick-taking card game. It is played by two pairs of players, one pair against the other pair. Partners sit opposite each other at a table. In face-to-face games, a convenient table size is from 32 to 40 inches (80 to 100 centimeters) square. The table is usually covered by green baize cloth. The point of the cloth is to stop cards skittering (sliding) across the table. In online computer play, players from anywhere in the world sit at a virtual table. Millions of people play bridge in clubs, tournaments, online and with friends at home. It is one of the world's most popular card games. The World Bridge Federation is the governing body for international competitive bridge. The game is played in a number of "deals". Each deal goes through four phases: dealing the cards, the auction (also referred to as bidding), playing the cards, and scoring the results. Duplicate bridge. Most club and tournament play uses duplicate bridge, where the cards are not re-dealt during a session. The same deals are played by most or all players. This allows comparative scoring. The method has one peculiarity: in competition between pairs, all boards count for an equal number of points. The same number of points are available on each and every board (hand). These points are distributed according to the scores. This is a fundamental difference between duplicate bridge pairs and rubber bridge. In duplicate play between teams, the original scoring method is used. This is because teams play the same set of boards at each table, but with the seating of players changed (N/S to E/W and E/W to N/S). Thus both teams play the same set of boards. History. Early history of bridge. It is played with the standard 52 cards in four suits. The game developed out of whist, which is a relatively old card game. Bridge developed in a series of stages from about 1890 to about 1930. The stages included bridge-whist and auction bridge, and the developments took place mostly in New York and London. The origin of the word "bridge" in this context is not really known. One
No is an English word which has a negative meaning. It is the opposite of the word Yes, which is a positive term. No is used when someone is turning away something. It is used when opposing an idea, as well. It can also be used in different figures of speech. In both sentences and talking, the words "No" and the word "Not" can both be used, though the word "No" is mainly used when speaking to other people. In some cases, however, "Not" is not acceptable, and vice versa. These words are not to be confused with the similar sounding words know and knot. Examples of proper usage of "No" and "Not": Examples of improper usage of "No" and "Not":
Lev Davidovich Bronstein ( (; also transliterated "Leo", "Lev", "Trotskii", "Trotski", "Trotskij" and "Trotzky"; 26 October (O.S.) = 7 November (N.S.), 1879 in Kropyvnytskyi (Russian Empire, now in Ukraine) - 21 August 1940 in Coyoacán, Mexico) was the pseudonym of Leib or Lev Davidovich Bronstein. He was a Russian revolutionary and political theoretician of Jewish-Ukrainian descent. After leading the Red Army in the Russian Civil War, he disagreed with other Bolsheviks. had to leave Russia, and was later killed under Stalin's orders. Life. Trotsky was a socialist and a Marxist. During the 1905 attempt at a revolution in Russia, Trotsky helped organize a committee of workers that was called the "soviet" in the Russian capital, Saint Petersburg. When the leader of the soviet was arrested, Trotsky took his place. Trotsky helped to expand on the idea of permanent revolution, a theory that had been originally thought up by Karl Marx. After the revolution's failure, Trotsky left Russia for his own safety. In 1917, he returned to Russia because of the Russian Revolution. He successfully helped to bring about communism in Russia and to defend it during the Russian Civil War while was in charge of the Red Army. After the death of the leader of the Bolsheviks, Vladimir Lenin, Trotsky became involved in a power struggle with Joseph Stalin for the leadership of the party. Trostsky lost despite being Lenin's preference, and Stalin came to power. Death. Trotsky had to leave Russia because of Stalin, who was now an enemy of Trotsky and wanted to harm him. In 1938, Trotsky founded the Fourth International. Stalin tried several times to assassinate Trotsky. Stalin had one of his spies, Ramón Mercarder from Spain, fatally stabbed Trotsky in Mexico in 1940 with the help of Lavrentiy Beria . Trotskyism. People who believe in Trotsky's ideas are called Trotskyists and follow Trotskyism. Trotskyism is seen as being a more democratic form of
The Second International (1889–1916) was an organization created on July 14, 1889, by socialist and labour parties who wanted to work together for international socialism. It continued the work of the First International, which stopped being an organization in 1886. However, it did not include the still-powerful anarcho-syndicalist movement and trade unions. Among the Second International's most famous actions were its 1889 declaration of May 1 as International Labor Day and its 1910 declaration of March 8 as International Women's Day. The International's permanent executive and information body was the International Socialist Bureau (ISB). It was located in Brussels and formed after the International's Paris Congress of 1900. Emile Vandervelde and Camille Huysmans of the Belgian Labour Party were its chair and secretary. Vladimir Lenin was a member from 1905. Dadabhai Nauroji attended its Paris commune in 1906.