344 résultats pour "back"
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Space Shuttle - astronomy.
The two SRBs, with their combined thrust of some 26 million newtons (about 5.8 million lb), provide most of the power for the first two minutes of flight. The SRBs takethe space shuttle to an altitude of 45 km (28 mi) and a speed of 4,973 km/h (3,094 mph) before they separate and fall back into the ocean to be retrieved,refurbished, and prepared for another flight. After the boosters fall away, the three main engines continue to provide thrust. These engines are clustered at the rear end of the...
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Paul Martin.
VI CONFLICT WITH THE PRIME MINISTER Martin’s success could not have been achieved without the support he received from Jean Chrétien. Yet relations between the two men continued to deteriorate. In partthis was because of their continuing disagreement about how best to deal with the separatist challenge in Québec. In the 1993 election, a majority of Québec seats hadgone to the Bloc Québécois, and in 1994 the provincial separatist party, the Parti Québécois, won election on a platform promising...
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Paul Martin - Canadian History.
VI CONFLICT WITH THE PRIME MINISTER Martin’s success could not have been achieved without the support he received from Jean Chrétien. Yet relations between the two men continued to deteriorate. In partthis was because of their continuing disagreement about how best to deal with the separatist challenge in Québec. In the 1993 election, a majority of Québec seats hadgone to the Bloc Québécois, and in 1994 the provincial separatist party, the Parti Québécois, won election on a platform promising...
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Autism.
may also repeat body movements, such as spinning, rocking, or flapping hands. When upset or excited, they may also harm themselves by skin-biting or head-banging. They may also show significant aggression toward other people or inanimateobjects, or may have episodes of extreme anger or frustration. D Associated Symptoms Some children with autism show other symptoms that do not contribute to the diagnosis of autism itself. Sensory sensitivity is quite common, especially to some textures, sounds,...
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Vice President of the United States.
naval operations. Located in northwest Washington at Massachusetts Avenue and 34th Street, the three-story Queen Anne-style house is within easy driving distance ofCapitol Hill and the White House. The vice president receives an annual salary of $189,300. The vice president has a staff and offices in the Everett M. Dirksen Senate Office Building, near the Capitol, toassist with legislative matters, as well as a personal office near the Senate lobby. The vice president also has staff and offices...
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Richard Nixon.
As President Eisenhower neared the end of his second term, his vice president emerged as his logical successor, and the president endorsed Nixon in March. Nixonreceived an impressive vote in party primaries, and at the Republican National Convention, held in Chicago in July, he received all but ten of the delegates’ votes on thefirst ballot. Nixon chose as his running mate the U.S. ambassador to the United Nations, Henry Cabot Lodge of Massachusetts. An unusual feature of the campaign wasa serie...
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Richard Nixon
As President Eisenhower neared the end of his second term, his vice president emerged as his logical successor, and the president endorsed Nixon in March. Nixonreceived an impressive vote in party primaries, and at the Republican National Convention, held in Chicago in July, he received all but ten of the delegates’ votes on thefirst ballot. Nixon chose as his running mate the U.S. ambassador to the United Nations, Henry Cabot Lodge of Massachusetts. An unusual feature of the campaign wasa serie...
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Television.
A charge-coupled device (CCD) can be much smaller than a camera tube and is much more durable. As a result, cameras with CCDs are more compact and portablethan those using a camera tube. The image they create is less vulnerable to distortion and is therefore clearer. In a CCD, the light from a scene strikes an array ofphotodiodes arranged on a silicon chip. Photodiodes are devices that conduct electricity when they are struck by light; they send this electricity to tiny capacitors. Thecapacitors...
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Crusades.
modern Lebanon; the Principality of Antioch, in modern Syria; and the County of Edessa, in modern northern Syria and southern Turkey. IV CRUSADES OF THE 12TH CENTURY The Crusades of the 12th century, through the end of the Third Crusade in 1192, illustrate the tensions and problems that plagued the enterprise as a whole. For thelords of Outremer a compromise with the residents and Muslim powers made sense; they could not live in constant warfare. And yet as European transplants theydepended on...
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Crusades .
modern Lebanon; the Principality of Antioch, in modern Syria; and the County of Edessa, in modern northern Syria and southern Turkey. IV CRUSADES OF THE 12TH CENTURY The Crusades of the 12th century, through the end of the Third Crusade in 1192, illustrate the tensions and problems that plagued the enterprise as a whole. For thelords of Outremer a compromise with the residents and Muslim powers made sense; they could not live in constant warfare. And yet as European transplants theydepended on...
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Detroit - geography.
of German and Irish immigrants. In the first half of the 20th century, the percentage of foreign-born residents declined, even though many immigrants arrived fromeastern Europe. During World War II (1939-1945), both whites and blacks were attracted from the South to work in the city’s defense industries. In 1950 foreign-bornand black residents each made up about 16 percent of the total population. In the five decades after 1950, the city lost almost half of its population, as many white resident...
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George Herbert Walker Bush.
Lebanon. More troubling was the disclosure that agents operating under direct White House supervision used profits from the arms sales to buy weapons for thecontras, a group of anti-government Nicaraguan rebels, despite an explicit congressional ban on such aid. Bush later claimed that he opposed the arms-for-hostagesdeal, but offered little evidence to back his claims ( see Iran-Contra Affair). C 1988 Presidential Election While the Reagan-Bush program helped produce prosperity for the wealth...
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George Herbert Walker Bush - USA History.
Lebanon. More troubling was the disclosure that agents operating under direct White House supervision used profits from the arms sales to buy weapons for thecontras, a group of anti-government Nicaraguan rebels, despite an explicit congressional ban on such aid. Bush later claimed that he opposed the arms-for-hostagesdeal, but offered little evidence to back his claims ( see Iran-Contra Affair). C 1988 Presidential Election While the Reagan-Bush program helped produce prosperity for the wealth...
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African Literature
I
INTRODUCTION
African Literature, oral and written literature produced on the African continent.
that few scholars of African culture know any African languages, and few Africans know an African language other than their own. The best-known literatures in Africanlanguages include those in Yoruba and Hausa in West Africa; Sotho, Xhosa, and Zulu in southern Africa; and Amharic, Somali, and Swahili in East Africa. In West Africa, Yoruba writing emerged after Bishop Ajayi Crowther, a former slave, developed a script for the language and in 1900 published the first Yorubatranslation of the Bible...
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Mythology.
Across cultures, mythologies tend to describe similar characters. A common character is the trickster. The trickster is recklessly bold and even immoral, but through hisinventiveness he often helps human beings. In Greek mythology, Hermes (best known as the messenger of the gods) was a famous trickster. In one version of acharacteristic tale, Hermes, while still an infant, stole the cattle of his half-brother Apollo. To avoid leaving a trail that could be followed, Hermes made shoes from thebark...
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History of United States Business.
their lives. But the rewards were worth it; a few lucrative voyages and a merchant could buy a townhouse, a carriage, perhaps a summer retreat. The merchant couldclimb the social ladder and circulate among the powerful in this highly materialistic society. This prospect of riches and the honor that accompanied them made Americancolonists willing to engage in highly speculative enterprises, such as shipping flour to the West Indies or importing goods from England by the thousands without beingcer...
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Harry S.
B2 Presiding Judge Political machines, such as the Pendergast organization, were common to both parties in the 1920s. They were based on the spoils system, in which winning politiciansgave government jobs to those loyal party members who had helped them get elected. Using government jobs as rewards, politicians created efficient (and oftenalmost unstoppable) vote-getting “machines,” in which party loyalty was often more important than doing any work. Without local machine support a political ca...
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Harry S.
B2 Presiding Judge Political machines, such as the Pendergast organization, were common to both parties in the 1920s. They were based on the spoils system, in which winning politiciansgave government jobs to those loyal party members who had helped them get elected. Using government jobs as rewards, politicians created efficient (and oftenalmost unstoppable) vote-getting “machines,” in which party loyalty was often more important than doing any work. Without local machine support a political ca...
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Croatia - country.
III PEOPLE OF CROATIA The total population of Croatia at the time of the 1991 census was 4,784,265; a 2008 estimate was 4,491,543. During and after the war ethnic Serbs fled Croatia whileethnic Croats moved in. Croatia’s population growth rate in 2008 was -0.04 percent, despite population gains due to immigration. Croatia’s natural population growthrate, which measures births and deaths, has been negative since 1998. Life expectancy at birth was 75 years in 2008. The population density in 2008...
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Latvia - country.
The population of Latvia is about 2,245,423 (2008 estimate), yielding an average population density of 35 persons per sq km (91 per sq mi). Latvia is highly urbanized.Some 66 percent of the population lives in urban areas, with nearly one-third of the total population residing in the capital, Rīga. Other important cities includeDaugavpils, an industrial center in the southeast, on the Daugava River; Liep āja, an important port on the Baltic Sea; Jelgava, an industrial center near Rîga; J ūrmala,...
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Cell (biology) - biology.
proteins, or other proteins required by the cell. While relatively simple in construction, prokaryotic cells display extremely complex activity. They have a greater range of biochemical reactions than those found in theirlarger relatives, the eukaryotic cells. The extraordinary biochemical diversity of prokaryotic cells is manifested in the wide-ranging lifestyles of the archaebacteria andthe bacteria, whose habitats include polar ice, deserts, and hydrothermal vents—deep regions of the ocean un...
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Ulysses S.
In the autumn of 1862, Grant began planning the drive on Vicksburg, Mississippi, the Confederate stronghold on the Mississippi River, which was to yield one of hisgreatest military successes. After several unsuccessful attempts on Vicksburg during the winter, Grant devised a new strategy of attack. In April 1863 he marched hisarmy south along the west side of the river to a point well below the heavily defended city. There, with the aid of the Union river fleet, he crossed the river and began as...
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Ulysses S.
In the autumn of 1862, Grant began planning the drive on Vicksburg, Mississippi, the Confederate stronghold on the Mississippi River, which was to yield one of hisgreatest military successes. After several unsuccessful attempts on Vicksburg during the winter, Grant devised a new strategy of attack. In April 1863 he marched hisarmy south along the west side of the river to a point well below the heavily defended city. There, with the aid of the Union river fleet, he crossed the river and began as...
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Native American Art.
folding, braiding or weaving, could also be sewn onto the hide. The production of decorated clothing and bags increased after contact with Europeans as a greater variety of textiles and other materials became available throughtrade. Imported glass beads inspired native women, who quickly adapted quillwork techniques for the creation of beaded apparel. European curvilinear and floraldesigns of the 19th century proved as meaningful for the native women who worked with them as they were for the non...
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British Columbia - Geography.
hemlock, Douglas fir, Sitka spruce, and various cedars, grows rapidly in the mild, wet climate and produces the largest trees in Canada. In the dry lowlands of thesouthern and central interior, ponderosa and lodgepole pines, aspen, and bunchgrass are characteristic. Spruce dominates the Prince George region. Prairie grasses andstands of aspen are found in the northeastern corner of the province. At elevations higher than about 1,800 m (about 6,000 ft), an alpine vegetation of shrubs, mosses,and...
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British Columbia - Canadian History.
hemlock, Douglas fir, Sitka spruce, and various cedars, grows rapidly in the mild, wet climate and produces the largest trees in Canada. In the dry lowlands of thesouthern and central interior, ponderosa and lodgepole pines, aspen, and bunchgrass are characteristic. Spruce dominates the Prince George region. Prairie grasses andstands of aspen are found in the northeastern corner of the province. At elevations higher than about 1,800 m (about 6,000 ft), an alpine vegetation of shrubs, mosses,and...
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Bird.
I
INTRODUCTION
Bird, animal with feathers and wings. Birds are the only
B Physical Adaptations for Flight The internal body parts of all birds, including flightless ones, reflect the evolution of birds as flying creatures. Birds have lightweight skeletons in which many of themajor bones are hollow. A unique feature of birds is the furculum, or wishbone, which is comparable to the collarbones of humans, although in birds the left and rightportions are fused together. The furculum absorbs the shock of wing motion and acts as a spring to help birds breathe while they...
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Bird - biology.
B Physical Adaptations for Flight The internal body parts of all birds, including flightless ones, reflect the evolution of birds as flying creatures. Birds have lightweight skeletons in which many of themajor bones are hollow. A unique feature of birds is the furculum, or wishbone, which is comparable to the collarbones of humans, although in birds the left and rightportions are fused together. The furculum absorbs the shock of wing motion and acts as a spring to help birds breathe while they...
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Stone Age.
limestone, quartzite, and indurated shale. Ground stone tools could be made on a wider range of raw material types, including coarser grained rock such as granite. Flaking produces several different types of stone artifacts, which archaeologists look for at prehistoric sites. The parent pieces of rock from which chips have beendetached are called cores, and the chips that have been removed from cores are called flakes. A flake that has had yet smaller flakes removed from one or more edgesin orde...
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Orthodox Church.
formally defined by an ecumenical council, as it was in Catholicism, some Orthodox theologians have taught that the act of becoming a monk or the service of burial canalso be sacraments. The sacramental practice of the Orthodox differs in many details from Western customs. Baptism is administered by immersing the child or adult three times under thewater, each time in the name of one of the persons of the Trinity. It is followed immediately by anointment with chrism, a sacred perfumed oil that r...
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Idaho - geography.
Idaho-Montana state line in the southern part of the Bitterroot Mountains. Consequently, nearly all the rivers in the state drain toward the Pacific. Most of Idaho lieswithin the drainage basin of the Columbia River system. The Snake River, which is the chief river in southern and central Idaho, follows a crescent-shaped course forabout 790 km (about 490 mi) across southern Idaho. It then swings northward along the Idaho state line and joins the Columbia River in Washington. Major tributariesof...
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Idaho - USA History.
Idaho-Montana state line in the southern part of the Bitterroot Mountains. Consequently, nearly all the rivers in the state drain toward the Pacific. Most of Idaho lieswithin the drainage basin of the Columbia River system. The Snake River, which is the chief river in southern and central Idaho, follows a crescent-shaped course forabout 790 km (about 490 mi) across southern Idaho. It then swings northward along the Idaho state line and joins the Columbia River in Washington. Major tributariesof...
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Rocket.
the vacuum of space, however, demonstrated that this belief was not true. In fact, rockets produce more thrust in the vacuum of space than on Earth. Air pressure andfriction with the air reduce a rocket’s thrust by about 10 percent on Earth as compared to the rocket’s performance in space. B Thrust and Efficiency Thrust is a measurement of the force of a rocket, or the amount of “push” exerted backward to move a rocket forward. Thrusts vary greatly from rocket to rocket.Engineers measure thrust...
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Rocket - astronomy.
the vacuum of space, however, demonstrated that this belief was not true. In fact, rockets produce more thrust in the vacuum of space than on Earth. Air pressure andfriction with the air reduce a rocket’s thrust by about 10 percent on Earth as compared to the rocket’s performance in space. B Thrust and Efficiency Thrust is a measurement of the force of a rocket, or the amount of “push” exerted backward to move a rocket forward. Thrusts vary greatly from rocket to rocket.Engineers measure thrust...
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Native Americans of North America.
addition to smallpox and measles, explorers and colonists brought a host of other diseases: bubonic plague, cholera, typhoid fever, scarlet fever, pleurisy, mumps,diphtheria, pneumonia, whooping cough, malaria, yellow fever, and various sexually transmitted infections. Despite the undisputed devastation wreaked on Indian populations after European contact, native populations showed enormous regional variability in their response todisease exposure. Some peoples survived and, in some cases, even...
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Native Americans of North America - Canadian History.
addition to smallpox and measles, explorers and colonists brought a host of other diseases: bubonic plague, cholera, typhoid fever, scarlet fever, pleurisy, mumps,diphtheria, pneumonia, whooping cough, malaria, yellow fever, and various sexually transmitted infections. Despite the undisputed devastation wreaked on Indian populations after European contact, native populations showed enormous regional variability in their response todisease exposure. Some peoples survived and, in some cases, even...
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THE ALCHIMIST
Pau lo C oelh o - T he A lc h em is t 2 o f 6 8 w ho l iv ed i n t h e v illa g e t h ey w ould r e ach i n a b out f o ur d ay s. H e h ad b een t o t h e v illa g e o nly o n ce, t h e y ear b efo re . T he m erc h an t w as t h e p ro prie to r o f a d ry g oods s h op, a n d h e a lw ay s d em an ded t h at t h e s h eep b e s h eare d i n h is p re se n ce, s o t h at h e w ould n ot b e c h eate d . A f r ie n d h ad t o ld t h e b oy a b out t h e s h op, a n d...
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United States History - U.
and improved upon the designs of Arab sailing ships and learned to mount cannons on those ships. In the 15th century they began exploring the west coast ofAfrica—bypassing Arab merchants to trade directly for African gold and slaves. They also colonized the Madeira Islands, the Azores, and the Cape Verde Islands andturned them into the first European slave plantations. The European explorers were all looking for an ocean route to Asia. Christopher Columbus sailed for the monarchs of Spain in 149...
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United States History - U.
and improved upon the designs of Arab sailing ships and learned to mount cannons on those ships. In the 15th century they began exploring the west coast ofAfrica—bypassing Arab merchants to trade directly for African gold and slaves. They also colonized the Madeira Islands, the Azores, and the Cape Verde Islands andturned them into the first European slave plantations. The European explorers were all looking for an ocean route to Asia. Christopher Columbus sailed for the monarchs of Spain in 149...
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Global Warming.
some of the warming influence of increasing greenhouse gases. A1 Carbon Dioxide Carbon dioxide is the second most abundant greenhouse gas, after water vapor. Carbon dioxide constantly circulates in the environment through a variety of naturalprocesses known as the carbon cycle. It is released into the atmosphere from natural processes such as eruptions of volcanoes; the respiration of animals, whichbreathe in oxygen and exhale carbon dioxide; and the burning or decay of plants and other organic...
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Canada.
Six general landform regions are distinguishable in Canada: the Appalachian Region, the Great Lakes and St. Lawrence Lowlands, the Canadian Shield, the Great Plains,the Canadian Cordillera, and the Canadian Arctic Archipelago. B1 Appalachian Region and Great Lakes and St. Lawrence Lowlands Eastern Canada consists of the Appalachian Region and the Great Lakes and St. Lawrence Lowlands. The Appalachian Region embraces Newfoundland Island, NovaScotia, New Brunswick, Prince Edward Island, and the G...
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Canada - country.
Six general landform regions are distinguishable in Canada: the Appalachian Region, the Great Lakes and St. Lawrence Lowlands, the Canadian Shield, the Great Plains,the Canadian Cordillera, and the Canadian Arctic Archipelago. B1 Appalachian Region and Great Lakes and St. Lawrence Lowlands Eastern Canada consists of the Appalachian Region and the Great Lakes and St. Lawrence Lowlands. The Appalachian Region embraces Newfoundland Island, NovaScotia, New Brunswick, Prince Edward Island, and the G...
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Canada - Canadian History.
Six general landform regions are distinguishable in Canada: the Appalachian Region, the Great Lakes and St. Lawrence Lowlands, the Canadian Shield, the Great Plains,the Canadian Cordillera, and the Canadian Arctic Archipelago. B1 Appalachian Region and Great Lakes and St. Lawrence Lowlands Eastern Canada consists of the Appalachian Region and the Great Lakes and St. Lawrence Lowlands. The Appalachian Region embraces Newfoundland Island, NovaScotia, New Brunswick, Prince Edward Island, and the G...
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France - country.
In both the Paris and Aquitaine basins, fertile soils derived from limestone and wind-deposited dust, called loess, have supported prosperous agriculture since ancienttimes. Other lowlands in France are scattered and relatively small. They include the Alsace Plain in the east, bordering Germany, the valley of the Rhône River in thesoutheast, and the Languedoc Plain along the Mediterranean coast. A2 Uplands France contains several regions of uplands, the worn down remains of ancient mountain sys...