136 résultats pour "heavy"
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Mechanics
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INTRODUCTION
Mechanics, branch of physics concerning the motions of objects and their response to forces.
Components of VelocityNeglecting air resistance, a ball thrown into the air at an angle will travel in a parabolic path. The velocity of the ball (V)has independent vertical (V) and horizontal (H) components; the horizontal component stays the same the entire time theball is in the air, while the vertical component, the only component affected by gravity, changes continuously while theball is aloft.© Microsoft Corporation. All Rights Reserved. To understand why and how objects accelerate, force...
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Iranian Art and Architecture
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INTRODUCTION
Iranian Art and Architecture, the visual arts of Iran.
The first great development of ancient Persian architecture took place under the Achaemenid dynasty during the Persian Empire, from about 550 to 330 BC. Remains of Achaemenian architecture are numerous, the earliest being ruins at Pasargadae, the capital city of Cyrus the Great. These ruins include two palaces, a sacred precinct, acitadel, a tower, and the tomb of Cyrus. The palaces were set in walled gardens and contained central columnar halls, the largest of which was 37 m (111 ft) in length...
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Fossil Fuels.
water molecules. This crystalline solid is known as gas hydrate. Because technology for the commercial extraction of gas hydrates has not yet been developed, this typeof fossil fuel is not included in most world energy resource estimates. However, in February 2007 the U.S. Department of Energy completed the drilling of a well toretrieve core samples of gas hydrates found in the Prudhoe Bay region of Alaska’s North Slope. By identifying the nature of these gas hydrates, the Energy Departmenthoped...
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D-Day Invasion.
The Allied planners focused on the beaches around Caen and the Cotentin Peninsula in northern France rather than those of Calais, even though it meant the forcewould be crossing at a wider part of the English Channel. That disadvantage was far outweighed by what the site offered: comparatively scanty defensive fortificationsand beachhead ideally suited for successful exits. The clincher was an isolated battlefield that the Germans would have difficulty reinforcing. The date was set for May 1, 19...
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Cleveland (Ohio) - geography.
Cleveland Children’s Museum. Also located in University Circle is Severance Hall, the home of the world-acclaimed Cleveland Orchestra. Nearby is the Cleveland PlayHouse, with three large, restored theaters and one of the largest non-profit professional theaters in the country. Downtown is Playhouse Square Center, with fourrecently restored theaters, home to the Cleveland Opera and the Great Lakes Theater Festival. On the waterfront is the Rock and Roll Hall of Fame and Museum,opened in 1995 and...
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Pittsburgh - geography.
College of Allegheny County (1966), with branches in the city and suburbs. Pittsburgh has many outstanding cultural institutions. The Oakland district is where Carnegie Mellon University and the University of Pittsburgh are located. The CarnegieMuseums of Pittsburgh include The Carnegie Museum of Art (including the Scaife Galleries), which holds a distinguished motion-picture and video collection and a uniquestudy of architecture; the Carnegie Museum of Natural History, which displays an extensi...
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Supernova - astronomy.
The term hypernova has been proposed for an extremely massive core-collapse supernova—possibly more than 100 times the mass of the Sun. A hypernova is thought to form a black hole. Just before it explodes, a hypernova may release a huge burst of gamma rays in a jet from the rotating black hole at its center. These jets mayexplain the so-called long gamma-ray bursts detected by astronomers. According to some researchers, massive stars with over 40 solar masses may sometimescollapse directly int...
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Conservation.
cancers, Hodgkin’s disease and leukemia. Unfortunately, human activities have greatly reduced biodiversity around the world. The 20th century encompasses one of the greatest waves of extinction, orelimination of species, to occur on the planet. The greatest threat to biodiversity is loss of habitat as humans develop land for agriculture, grazing livestock, industry,and habitation. The most drastic damage has occurred in the tropical rain forests, which cover less than seven percent of the Earth’...
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Nuclear Weapons.
Regardless of the method used to attain a supercritical assembly, the chain reaction proceeds for about a millionth of a second, liberating vast amounts of heat energy.The extremely fast release of a very large amount of energy in a relatively small volume causes the temperature to rise to tens of millions of degrees. The resultingrapid expansion and vaporization of the bomb material causes a powerful explosion. VI PRODUCTION OF FISSILE MATERIAL Much experimentation was necessary to make the p...
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Bosnia and Herzegovina - country.
Serb military campaigns in 1992 and 1993 and Croat campaigns in 1993 and 1995 were aimed at expelling others from areas claimed by these groups. By the end ofthe war almost all non-Serbs had been expelled from Serb-claimed lands in eastern and northern Bosnia, and non-Croats from Croat-claimed lands in southwesternBosnia. In turn, most non-Muslims had left land under Muslim control in northwestern Bosnia. The largest cities had mixed populations in 1991, but the war and its aftermath made them a...
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Arkansas - geography.
temperature rises to the upper 30°s C (lower 100°s F). C2 Precipitation Arkansas receives about 1,000 to 1,300 mm (about 40 to 50 in) of precipitation a year, and some areas receive even more. Most of the rain comes during winter andspring and at times is so heavy as to cause flooding. Snow is rare in the south but amounts to more than 250 mm (10 in) a year in the mountains. C3 Growing Season Arkansas has a long growing season. It averages 211 days for the state as a whole and ranges from 241...
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Arkansas - USA History.
temperature rises to the upper 30°s C (lower 100°s F). C2 Precipitation Arkansas receives about 1,000 to 1,300 mm (about 40 to 50 in) of precipitation a year, and some areas receive even more. Most of the rain comes during winter andspring and at times is so heavy as to cause flooding. Snow is rare in the south but amounts to more than 250 mm (10 in) a year in the mountains. C3 Growing Season Arkansas has a long growing season. It averages 211 days for the state as a whole and ranges from 241...
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Florida - USA History.
accidentally introduced into the region in the 1880s, and it spread with alarming rapidity throughout the upper reaches of the river. The plant is very difficult toeradicate, and it has also clogged the channels of other Florida rivers. To increase drainage of the Everglades, which drain naturally to Florida Bay and the Gulf ofMexico, a number of drainage channels and canals have been built across southern Florida. Among the rivers flowing from the peninsula to the Gulf of Mexico are the Suwanne...
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Korean War.
During the summer of 1949, South Korea had expanded its army to about 90,000 troops, a strength the North matched in early 1950. The North had about 150 SovietT-34 tanks and a small but effective air force of 70 fighters and 62 light bombers—weapons either left behind when Soviet troops evacuated Korea or bought from theUSSR and China in 1949 and 1950. By June 1950 American data showed the two armies at about equal strength, with roughly equal numbers amassed along the 38thparallel. However, thi...
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Korean War - History.
During the summer of 1949, South Korea had expanded its army to about 90,000 troops, a strength the North matched in early 1950. The North had about 150 SovietT-34 tanks and a small but effective air force of 70 fighters and 62 light bombers—weapons either left behind when Soviet troops evacuated Korea or bought from theUSSR and China in 1949 and 1950. By June 1950 American data showed the two armies at about equal strength, with roughly equal numbers amassed along the 38thparallel. However, thi...
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Korean War - U.
During the summer of 1949, South Korea had expanded its army to about 90,000 troops, a strength the North matched in early 1950. The North had about 150 SovietT-34 tanks and a small but effective air force of 70 fighters and 62 light bombers—weapons either left behind when Soviet troops evacuated Korea or bought from theUSSR and China in 1949 and 1950. By June 1950 American data showed the two armies at about equal strength, with roughly equal numbers amassed along the 38thparallel. However, thi...
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Slovakia - country.
The country is divided informally into the three regions of Western Slovakia, Central Slovakia, and Eastern Slovakia, corresponding to administrative divisions that wereabolished in 1989. Most of Slovakia’s 600,000 Hungarians live in the southern parts of Western and Central Slovakia, which served as the cultural center of Hungary forseveral centuries after Hungary proper was invaded by the Ottomans in the 16th century. The Ruthenian and Ukrainian minorities are concentrated in the northernregio...
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Bicycle.
narrow as possible to minimize weight and interference with pedaling. F Specialty Bicycles Many other types of bicycles are designed for special purposes. Although not as common as standard single-rider racing, touring, mountain, or recreational bicycles,they nonetheless have significant niches. Recumbent bicycles are bicycles on which the rider sits upright as if in a chair, with legs and feet stretched out in front. Because they support the rider’s lower back,recumbents allow the rider far mo...
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Connecticut - geography.
The state’s shoreline, when all the bays and inlets are taken into account, has a total length of 995 km (618 mi). The coastline is deeply indented by long estuaries androcky inlets, and there are many sandy beaches and stretches of tidal marsh. There are several good harbors along the coast, the most important of which is at NewHaven. A few small islands lie offshore in Long Island Sound. D Climate Connecticut has long, hot summers and cold winters. The climate does not vary greatly from place...
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Connecticut - USA History.
The state’s shoreline, when all the bays and inlets are taken into account, has a total length of 995 km (618 mi). The coastline is deeply indented by long estuaries androcky inlets, and there are many sandy beaches and stretches of tidal marsh. There are several good harbors along the coast, the most important of which is at NewHaven. A few small islands lie offshore in Long Island Sound. D Climate Connecticut has long, hot summers and cold winters. The climate does not vary greatly from place...
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Democratic Republic of the Congo - country.
Except in the high elevations, the country’s climate is very hot and humid. The average annual temperature in the low central area is about 27°C (about 80°F).Temperatures are considerably higher in February, the hottest month. At altitudes above about 1,500 m (about 5,000 ft) the average annual temperature is about 19°C(about 66°F). Average annual rainfall is about 1,500 mm (about 60 in) in the north and about 1,300 mm (about 50 in) in the south. Frequent heavy rains occur fromApril to November...
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Alberta - Geography.
C Climate Except for the mountain areas, summers throughout the province are quite warm. Winters are long and extremely cold. In July, average daily temperatures range fromabout 16°C (about 60°F) along the northern boundary to about 21°C (about 70°F) in the south. In the extreme southeastern section of the province, temperatures of43°C (110°F) have been recorded. In January, average daily temperatures range from about -14°C (about 6°F) at Grande Prairie to about -9°C (about 16°F) atCalgary. Tem...
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Alberta - Canadian History.
C Climate Except for the mountain areas, summers throughout the province are quite warm. Winters are long and extremely cold. In July, average daily temperatures range fromabout 16°C (about 60°F) along the northern boundary to about 21°C (about 70°F) in the south. In the extreme southeastern section of the province, temperatures of43°C (110°F) have been recorded. In January, average daily temperatures range from about -14°C (about 6°F) at Grande Prairie to about -9°C (about 16°F) atCalgary. Tem...
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Sweden - country.
mi) and is Sweden’s second largest lake, after Vänern. The two lakes, together with several smaller lakes, rivers, and canals, form an internal water route called theGöta Canal. Built in the early 19th century, the Göta Canal extends for about 386 km (about 240 mi) and provides a scenic transportation link between the Baltic Sea,at Stockholm, and the Kattegat. Sweden’s other large lakes in the district include Mälaren, Hjälmaren, and the famously picturesque Siljan. D Climate Although one-seven...
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Massachusetts - geography.
mi). Other large artificial lakes include Wachusett Reservoir, East Brimfield Reservoir, and Cobble Mountain Reservoir. Assawompsett Pond, covering about 10 sq km(about 4 sq mi), is the largest natural lake. North Watuppa Pond and Long Pond are other large natural lakes. Lake Chaubunagungamaug, near Webster, is usuallycalled Webster Lake, because the Algonquian name is difficult to pronounce and spell. The full version of the Native American name is said to be the longest place-namein North Amer...
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Kansas - geography.
at the adjoining cities of Kansas City, Kansas, and Kansas City, Missouri. Its chief headstreams are the Republican and Smoky Hill rivers, which join to form the KansasRiver at Junction City. Each of the headstreams has numerous tributaries. The Kansas River proper is only 270 km (170 mi) long, but the Smoky Hill River has a lengthof 870 km (540 mi), and the Republican River has a length of 720 km (450 mi). The main tributary flowing into the Kansas River is the Big Blue River. The Arkansas Rive...
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Kansas - USA History.
at the adjoining cities of Kansas City, Kansas, and Kansas City, Missouri. Its chief headstreams are the Republican and Smoky Hill rivers, which join to form the KansasRiver at Junction City. Each of the headstreams has numerous tributaries. The Kansas River proper is only 270 km (170 mi) long, but the Smoky Hill River has a lengthof 870 km (540 mi), and the Republican River has a length of 720 km (450 mi). The main tributary flowing into the Kansas River is the Big Blue River. The Arkansas Rive...
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Pennsylvania - geography.
B Rivers and Lakes There are three major river basins in Pennsylvania: the Susquehanna, the Ohio, and the Delaware. Together they drain more than 90 percent of Pennsylvania’s landarea. Most of eastern and central Pennsylvania is drained by the Susquehanna and Delaware systems. The western part of the state is drained by the Allegheny andMonongahela rivers, which join at Pittsburgh to form the Ohio. In addition to the three major river basins, short streams flowing into Lake Erie drain the north...
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Pennsylvania - USA History.
B Rivers and Lakes There are three major river basins in Pennsylvania: the Susquehanna, the Ohio, and the Delaware. Together they drain more than 90 percent of Pennsylvania’s landarea. Most of eastern and central Pennsylvania is drained by the Susquehanna and Delaware systems. The western part of the state is drained by the Allegheny andMonongahela rivers, which join at Pittsburgh to form the Ohio. In addition to the three major river basins, short streams flowing into Lake Erie drain the north...
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Helium - chemistry.
the bends. This synthetic atmosphere is also used in medicine to relieve sufferers of respiratory difficulties because helium moves more easily than nitrogen throughconstricted respiratory passages. In surgery, beams of ionized helium from synchrocyclotron sources are proving useful in treating eye tumors, by stabilizing or evenshrinking the tumors. Such beams are also used to shrink blood-vessel malformations in the brains of patients. Helium is used in inert-gas arc welding for light metals, s...
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Edmonton - Geography.
both of which built fur trading posts near present-day Edmonton in 1795. The posts were rebuilt several times, always along the North Saskatchewan River, whichprovided the traders’ main transportation route. The last move came in 1830, when Fort Edmonton was erected on the high bluff where the Alberta Legislature nowstands. For the next 50 years, the fort was the major trading center on the western plains. The modern city began to take shape after 1900, when central Alberta was opened to Europea...
- antiarmor weapons
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Excerpt from Richard II - anthology.
He may surrender. So we shall proceedWithout suspicion. YORK. I will be his conduct.Exit BOLINGBROKE. Lords, you that here are under our arrest,Procure your sureties for your days of answer.Little are we beholding to your love,And little looked for at your helping hands. Enter Richard and York RICHARD. Alack, why am I sent for to a kingBefore I have shook off the regal thoughtsWherewith I reigned? I hardly yet have learnedTo insinuate, flatter, bow, and bend my knee.Give sorrow leave awhile to t...
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I'd never loved Grandma more than I loved her right then.
So Iput mystory intoit. I pretended hewas Grandma, andIstarted atthe very beginning. I told himabout thetuxedo onthe chair, andhow Ihad broken thevase, andfound thekey, andthelocksmith, andthe envelope, andtheartsupply store.Itold himabout thevoice ofAaron Black,andhow Iwas soincredibly closetokissing Abby Black. Shedidn't sayshe didn't wantto,just that itwasn't agood idea.Itold himabout AbeBlack inConey Island, and Ada Black withthetwo Picasso paintings, andthebirds thatflew byMr. Black's windo...
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Miami (Florida) - geography.
VI EDUCATIONAL AND CULTURAL INSTITUTIONS Colleges and universities in the area include the University of Miami, Florida International University, Barry University, St. Thomas University, and Florida MemorialCollege. Miami-Dade Community College, one of the nation’s largest two-year colleges, has six campuses in the region. Leading museums include the Historical Museumof Southern Florida, the Miami Museum of Science, the Miami Art Museum, the Lowe Art Museum on the campus of the University of M...
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Dance
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INTRODUCTION
Dance
Archive Films/BBC Worldwide Americas, Inc.
features in its dance styles. The ordinary potential of the body can be expanded in dance, usually through long periods of specialized training. In ballet, for example, the dancer exercises to rotate,or turn out, the legs at the hips, making it possible to lift the leg high in an arabesque. In India, some dancers learn to choreograph their eyeballs and eyebrows.Costuming can extend the body's capabilities. Toe or pointe shoes, stilts, and flying harnesses are a few of the artificial aids employe...
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Lima (Peru) - geography.
home to a wide range of museums, many focusing on Peru’s indigenous heritage. These include the National Museum of Anthropology and Archaeology, the GoldMuseum of Peru, the Museum of the Central Reserve Bank, and the Rafael Larco Herrera Museum, which specializes in pre-Hispanic ceramics. Art and history museumsare also found in metropolitan Lima, including the National Museum of the Republic, the Museum of Peruvian Culture, and the Museum of the Inquisition, in the buildingwhere colonial Cathol...
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Army.
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INTRODUCTION
Army, military land forces of a nation, assembled, drilled, disciplined,
disappearance for several centuries of large standing armies in Europe. A Middle Ages Feudalism was based on a concept of local defense, each baron or landowner governing land that had been given him by the king, and each lord having his ownpersonal protective forces recruited from among men who worked for him. In return, each lord and his men were pledged to annual service to the monarch and couldbe called on in special instances, as in the defense of Christendom during the Crusades. National...
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Sailing.
the sails sweep across the decks of the vessel from one side to the other, and also because of the danger of breaking spars. In wild jibing, control can be lostmomentarily and, if the seas are high, a small boat can broach —that is, veer on its side with danger of swamping or capsizing. An unintentional jibe in a heavy wind frequently has enough force to break the masts of a vessel. When jibing intentionally, careful sailors always haul in on the boom while turning, so that the boom willtravel...
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Tobacco - biology.
quality cigars are made entirely by hand, most cigars are manufactured by machine. Chewing tobaccos are generally made from thick grades of leaves to which binders and flavorings are added. Chewing tobacco is formed by pressing the tobacco intoblocks known as plugs. Snuff is made by grinding tobacco into fine powder, which is then allowed to ferment for a long period of time. Frequently, snuff is scented withspices, such as jasmine or cloves. V TOBACCO INDUSTRY Over 6 million tons of commercial...
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Excerpt from Dombey and Son - anthology.
light. Rivers and seas were formed to float their ships; rainbows gave them promise of fair weather; winds blew for or against their enterprises; stars and planetscircled in their orbits, to preserve inviolate a system of which they were the centre. Common abbreviations took new meanings in his eyes, and had sole reference tothem. A.D. had no concern with anno Domini, but stood for anno Dombei—and Son. He had risen, as his father had before him, in the course of life and death, from Son to D...
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World War I .
and troops to Europe from the United States and other overseas sources. In 1914 Britain implemented a sea blockade of Germany to prevent the delivery of importssuch as food and war materials. The same year, Germany began using submarines to disrupt Allied seaborne traffic and prevent supplies from reaching Britain. In 1915Germany instituted a submarine blockade around Britain. From February 1915 to September 1915 and again in 1917, Germany used unrestricted submarine warfare,sinking ships withou...
- antiaircraft weapons
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Observatory - astronomy.
Ultraviolet radiation, X rays, and gamma rays have shorter wavelengths than visible light has. These types of radiation tell astronomers about the hottest and mostviolent phenomena in the universe. Earth’s atmosphere blocks most of this radiation, so astronomers must send their observatories above the atmosphere aboardballoons, rockets, or satellites. Ultraviolet telescopes are much like visible light telescopes, but X-ray telescopes must have special nested cylindrical mirrors to prevent Xrays...
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Spanish-American War.
A Blockade of Cuba The Navy’s basic job was to blockade the island of Cuba. If the Spanish army could be cut off from seaborne supplies from Spain, it could not maintain itself for longagainst the Cuban insurgents, let alone prepare to fight the U.S. forces. To maintain a successful blockade, the U.S. Navy would have to control the sea approaches toCuba. To accomplish this, the United States determined that the Spanish navy had to be destroyed wherever it was found. Thus the U.S. war objectives...
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Bahrain - country.
A Religion Almost all Bahrainis and the majority of nonnatives are followers of Islam (Muslims). About 70 percent of all native Bahrainis belong to the Shia branch of Islam, whilethe remainder, including the ruling al-Khalifa clan, are adherents of the Sunni branch. Non-Muslims, including Hindus, Buddhists, Christians, and Jews, account for 15percent of the total population. High unemployment among the Shia population has caused considerable discontent on the part of this group toward the Sunni...
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Tokyo - geography.
The port of Tokyo has expanded tremendously in recent years and is now the second largest in Japan (after Yokohama) in value of trade. In 1993 it accounted forapproximately 14 percent of all trade by Japan’s ports. Reasons for the port’s growth include the deepening of sea lanes in Tokyo Bay, large reclamation projects tocreate room for new facilities and container terminals, and improvements to storage and distribution facilities. The largest categories of exports from the port of Tokyoare mach...
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Turtle.
Turtles use their jaws to cut and handle food. Instead of teeth, a turtle’s upper and lower jaws are covered by horny ridges, similar to a bird’s beak. Meat-eating turtlescommonly have knife-sharp ridges for slicing through their prey. Plant-eating turtles often have ridges with serrated edges that help them cut through tough plants.Turtles use their tongues in swallowing food, but unlike many other reptiles, such as chameleons, they cannot stick out their tongues to capture food. C Limb Structu...
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Turtle - biology.
Turtles use their jaws to cut and handle food. Instead of teeth, a turtle’s upper and lower jaws are covered by horny ridges, similar to a bird’s beak. Meat-eating turtlescommonly have knife-sharp ridges for slicing through their prey. Plant-eating turtles often have ridges with serrated edges that help them cut through tough plants.Turtles use their tongues in swallowing food, but unlike many other reptiles, such as chameleons, they cannot stick out their tongues to capture food. C Limb Structu...
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Jordan (country) - country.
whom belong to the Greek Orthodox Church, make up about 4 percent of the population. Islam is the state religion and Arabic the official language. C Education Jordan has made significant strides in education in recent decades, despite the influx of hundreds of thousands of refugees and the very large share of the nationalbudget assigned to the armed forces. Public education is free and compulsory between the ages of 6 and 15. At the secondary level, about 85 percent of the malechildren and 87 p...