617 résultats pour "could"
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Manhattan Project - U.
other possible uses of nuclear energy, such as using uranium to operate large power plants or, perhaps, as power sources for ships or submarines. Then Nazi Germanyinvaded Poland on September 1, 1939, and Europe plunged into war. The scientists realized that any plans to build large-scale nuclear power plants would have to waituntil the war was over. Two weeks after the invasion of Poland, Hitler made a radio speech in which he threatened Britain with “a weapon against which there is no defense.”...
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Cloning - biology.
found that such embryo cells are totipotent (able to give rise to all the different cell types in the body). Exploiting this characteristic, scientists developed three techniques to clone embryo cells: blastomere separation, blastocyst division, and somatic cell nuclear transfer. A Blastomere Separation In blastomere separation, scientists fertilize an egg cell with a sperm cell in a laboratory dish. The resulting embryo is allowed to divide until it forms a mass of aboutfour cells. Scientist...
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Wireless Communications.
were large, heavy units. After the invention of the transistor in 1948, radios shrank in size to small handheld radio transceivers. Public two-way radios with severalfrequency options are widely available as well. Usually limited in range to a few miles, these units are great aids for such mobile professionals as construction workers,film crews, event planners, and security personnel. Simpler two-way radios, called walkie-talkies, have been popular children’s toys for years. Most walkie-talkiesb...
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Disputed Presidential Election of 2000 - U.
counts. At oral arguments on November 20, the justices seemed to be most interested in one issue: At what point did allowing re-counts risk making Florida too late toparticipate in the electoral college vote? Gore’s lawyers, led by David Boies, argued that the state had until December 12 to pick its electors, which allowed plenty oftime for the re-counts. Electors from each state would meet on December 18 to cast their votes. The next day the court ruled unanimously for Gore and granted a five-d...
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Excerpt from Emma - anthology.
Her sister, though comparatively but little removed by matrimony, being settled in London, only sixteen miles off, was much beyond her daily reach; and many along October and November evening must be struggled through at Hartfield, before Christmas brought the next visit from Isabella and her husband and their littlechildren to fill the house and give her pleasant society again. Highbury, the large and populous village almost amounting to a town, to which Hartfield, in spite of its separate...
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Galileo
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INTRODUCTION
Galileo (1564-1642), Italian physicist and astronomer who, with German astronomer Johannes Kepler, initiated the scientific revolution that flowered in the work of
English physicist Sir Isaac Newton.
V WORK IN ASTRONOMY During most of his time in Padua, Galileo showed little interest in astronomy, although in 1595 he declared in a letter that he preferred the Copernican theory that Earthrevolves around the Sun to the assumptions of Aristotle and Ptolemy that planets circle a fixed Earth ( see Astronomy: The Copernican Theory ; Ptolemaic System). A Observations with the Telescope In 1609 Galileo heard that a telescope had been invented in Holland. In August of that year he constructed a t...
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Galileo.
V WORK IN ASTRONOMY During most of his time in Padua, Galileo showed little interest in astronomy, although in 1595 he declared in a letter that he preferred the Copernican theory that Earthrevolves around the Sun to the assumptions of Aristotle and Ptolemy that planets circle a fixed Earth ( see Astronomy: The Copernican Theory ; Ptolemaic System). A Observations with the Telescope In 1609 Galileo heard that a telescope had been invented in Holland. In August of that year he constructed a t...
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Sir Robert Borden.
of the British Empire, Laurier proposed creating a Canadian navy that in case of war could be incorporated into the British navy. The plan was opposed by theConservatives, who thought that Canada should simply provide ships for the British navy. The Québec nationalists also opposed the plan because they did not wantCanada either to participate in the British navy or to have a navy of its own. At the last moment before election day in 1911 it looked as if the Liberals might win. The government ne...
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Sir Robert Borden - Canadian History.
of the British Empire, Laurier proposed creating a Canadian navy that in case of war could be incorporated into the British navy. The plan was opposed by theConservatives, who thought that Canada should simply provide ships for the British navy. The Québec nationalists also opposed the plan because they did not wantCanada either to participate in the British navy or to have a navy of its own. At the last moment before election day in 1911 it looked as if the Liberals might win. The government ne...
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Great Depression in the United States - U.
prices would continue to rise and they could soon sell their stocks at a profit. The widespread belief that anyone could get rich led many less affluent Americans into the market as well. Investors bought millions of shares of stock “on margin,” arisky practice similar to buying products on credit. They paid only a small part of the price and borrowed the rest, gambling that they could sell the stock at a highenough price to repay the loan and make a profit. For a time this was true: In 1928 the...
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Industrial Revolution
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INTRODUCTION
Industrial Revolution, widespread replacement of manual labor by machines that began in Britain in the 18th century and is still continuing in some parts of the world.
The most important advance in iron production occurred in 1784 when Englishman Henry Cort invented new techniques for rolling raw iron, a finishing process thatshapes iron into the desired size and form. These advances in metalworking were an important part of industrialization. They enabled iron, which was relativelyinexpensive and abundant, to be used in many new ways, such as building heavy machinery. Iron was well suited for heavy machinery because of its strength anddurability. Because of t...
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Industrial Revolution .
The most important advance in iron production occurred in 1784 when Englishman Henry Cort invented new techniques for rolling raw iron, a finishing process thatshapes iron into the desired size and form. These advances in metalworking were an important part of industrialization. They enabled iron, which was relativelyinexpensive and abundant, to be used in many new ways, such as building heavy machinery. Iron was well suited for heavy machinery because of its strength anddurability. Because of t...
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Relativity
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INTRODUCTION
Albert Einstein
In 1905 German-born American physicist Albert Einstein published his first paper outlining the theory of relativity.
in calculating very large distances or very large aggregations of matter. As the quantum theory applies to the very small, so the relativity theory applies to the verylarge. Until 1887 no flaw had appeared in the rapidly developing body of classical physics. In that year, the Michelson-Morley experiment, named after the American physicistAlbert Michelson and the American chemist Edward Williams Morley, was performed. It was an attempt to determine the rate of the motion of the earth through t...
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John Diefenbaker.
only Conservative elected from Saskatchewan, which had gone solidly to the Co-operative Commonwealth Federation (CCF), a coalition party dedicated to social andwelfare reforms. In 1952 the Liberals in Saskatchewan abolished Diefenbaker's Lake Centre seat altogether by merging it with the neighboring legislative district of Moose Jaw, where theCCF had a vast majority. In 1953 Diefenbaker decided to run for election in Prince Albert. Again he was the only Conservative returned to Parliament fromSa...
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John Diefenbaker - Canadian History.
only Conservative elected from Saskatchewan, which had gone solidly to the Co-operative Commonwealth Federation (CCF), a coalition party dedicated to social andwelfare reforms. In 1952 the Liberals in Saskatchewan abolished Diefenbaker's Lake Centre seat altogether by merging it with the neighboring legislative district of Moose Jaw, where theCCF had a vast majority. In 1953 Diefenbaker decided to run for election in Prince Albert. Again he was the only Conservative returned to Parliament fromSa...
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Electronic Music
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INTRODUCTION
Electronic Music, music that requires the use of electronic devices to produce or manipulate sound during its composition and performance.
III SYNTHESIZERS AND OTHER ELECTRONIC TECHNOLOGY Moog SynthesizerThe musical synthesizer was invented by American Robert Moog. Soon after Moog introduced an early version in 1964, itbecame known as the “Moog Synthesizer,” and then simply as the “Moog.” Here, Japanese composer Isao Tomita uses aMoog synthesizer in his studio.Huynh Cong/AP/Wide World Photos In the 1950s sound synthesizers were developed, principally in the United States. Synthesizers enabled composers to produce sounds electroni...
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Stem Cell.
The medical profession used adult stem cells to treat diseases long before anyone isolated one. In 1968 scientists performed the first successful bone marrowtransplant, a procedure in which a patient receives an infusion of healthy bone marrow cells. The purpose of such transplants is to restore the blood-making capabilitiesof the patient’s diseased bone marrow after extremely strong chemotherapy has destroyed that bone marrow. From the beginning investigators suspected that stemcells in the inf...
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Thomas Edison.
While Edison was working on the electric light, he made a scientific discovery that would become important to future generations. Edison noticed that particles of carbonfrom the filament blackened the insides of his light bulbs. This effect was caused by the emission of electrons from the filament, although Edison made the discoverybefore he and other scientists knew the electron existed. Not until 1897 did British physicist J. J. Thomson prove that the blackening observed by Edison was caused b...
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Thomas Edison - USA History.
While Edison was working on the electric light, he made a scientific discovery that would become important to future generations. Edison noticed that particles of carbonfrom the filament blackened the insides of his light bulbs. This effect was caused by the emission of electrons from the filament, although Edison made the discoverybefore he and other scientists knew the electron existed. Not until 1897 did British physicist J. J. Thomson prove that the blackening observed by Edison was caused b...
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Nanotechnology.
ever-finer method of reducing material to the nanoscale size. Instead, nanostructures would be assembled atom by atom and molecule by molecule, from the atomiclevel up, just as occurs in nature. However, assembly at this scale has its own challenges. In school, children learn about some of these challenges when they study the random Brownian motion seen in particles suspended in liquids such as water. Theparticles themselves are not moving. Rather, the water molecules that surround the particles...
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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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Black Death.
disappeared in the West. V DISAPPEARANCE OF PLAGUE Plague became less common in Europe after the 1530s. The last plague in England was in 1665, the last in Western Europe in 1722. Numerous theories have beenoffered to explain the disappearance of plague. It has been argued that black rats, the primary carriers of plague, may have been replaced by larger brown rats that donot carry the infection. A second theory suggests that increased immunity among the rodents that carried the disease or chang...
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Black Death .
disappeared in the West. V DISAPPEARANCE OF PLAGUE Plague became less common in Europe after the 1530s. The last plague in England was in 1665, the last in Western Europe in 1722. Numerous theories have beenoffered to explain the disappearance of plague. It has been argued that black rats, the primary carriers of plague, may have been replaced by larger brown rats that donot carry the infection. A second theory suggests that increased immunity among the rodents that carried the disease or chang...
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Astrobiology - astronomy.
water to help reactions along. American chemists Stanley Miller and Harold Urey tested part of Oparin and Haldane’s hypothesis in the early 1950s by simulating conditions of the early Earth. In whathas become known as the Miller-Urey experiment, the two scientists connected two flasks with a loop of glass tubing that allowed the gases to pass between the flasks.They filled the upper flask with methane, ammonia, and hydrogen—components thought to have been in the early atmosphere. They filled the...
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History of Astronomy - astronomy.
Egypt, the Sun was directly overhead at noon. On the same date and time in Alexandria, Egypt, the Sun was about 7 degrees south of zenith. With simple geometryand knowledge of the distance between the two cities, he estimated the circumference of the Earth to be 250,000 stadia. (The stadium was a unit of length, derivedfrom the length of the racetrack in an ancient Greek stadium. We have an approximate idea of how big an ancient Greek stadium was, and based on that approximationEratosthenes was...
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War of 1812 - History.
the thorough training they received in handling guns was far ahead of contemporary British standards. As hostilities loomed, Congress authorized a regular army of 35,000 men, but when the United States officially declared war in June 1812, the actual land force was lessthan 10,000 and nearly half of these soldiers were raw recruits. The existing troops were also widely scattered in small garrisons. The government planned tosupplement this regular force with 50,000 volunteers and 100,000 militiam...
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War of 1812 - U.
the thorough training they received in handling guns was far ahead of contemporary British standards. As hostilities loomed, Congress authorized a regular army of 35,000 men, but when the United States officially declared war in June 1812, the actual land force was lessthan 10,000 and nearly half of these soldiers were raw recruits. The existing troops were also widely scattered in small garrisons. The government planned tosupplement this regular force with 50,000 volunteers and 100,000 militiam...
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American Westward Movement - U.
British expansion. However, Native Americans of the Great Lakes and Ohio Valley lashed out against the English in an attempt to preserve their independence, theirland, and their way of life. With the Ottawa chief Pontiac as their most visible leader, the tribes waged a bloody and costly war. As a result, the British governmentdecided to keep the white settlers apart from the Native Americans. It issued the Royal Proclamation of 1763, banning all white settlement beyond the Appalachians andstatin...
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Persian Gulf War.
to “use all necessary means” to force Iraq from Kuwait if Iraq remained in the country after January 15, 1991. The Iraqis rejected the ultimatum. Soon after the vote,the United States agreed to a direct meeting between Secretary of State James Baker and Iraq’s foreign minister. The two sides met on January 9. Neither offered tocompromise. The United States underscored the ultimatum, and the Iraqis refused to comply with it, even threatening to attack Israel. For the United States, themeeting was...
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Persian Gulf War - History.
to “use all necessary means” to force Iraq from Kuwait if Iraq remained in the country after January 15, 1991. The Iraqis rejected the ultimatum. Soon after the vote,the United States agreed to a direct meeting between Secretary of State James Baker and Iraq’s foreign minister. The two sides met on January 9. Neither offered tocompromise. The United States underscored the ultimatum, and the Iraqis refused to comply with it, even threatening to attack Israel. For the United States, themeeting was...
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Persian Gulf War - U.
to “use all necessary means” to force Iraq from Kuwait if Iraq remained in the country after January 15, 1991. The Iraqis rejected the ultimatum. Soon after the vote,the United States agreed to a direct meeting between Secretary of State James Baker and Iraq’s foreign minister. The two sides met on January 9. Neither offered tocompromise. The United States underscored the ultimatum, and the Iraqis refused to comply with it, even threatening to attack Israel. For the United States, themeeting was...
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SUJET NATIONAL, SESSION DE JUIN 1995 LANGUE VIVANTE 1- SÉRIES ES/S
Tuen her voice again. "Y es." "What have you got?" The first voice. "What have you got there 30 in the back?" Her voice. "Old clothes. I'm making a collection for China War Relief." The first voice. "We'll have a look, if you don't mind." Her voice. "Go right ahead." 35 The sound of the door opening. The sound of the blonde girl mo- ving over so that the policemen could gain access to the back seat. He started to picture it again. Th...
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Hurricane.
V HOW HURRICANES ARE DETECTED AND MONITORED Since 1943 U.S. military and civilian aircraft have been flying into hurricanes to measure wind velocities and directions, the location and size of the eye, air pressures,and temperatures in different parts of the storm. A coordinated system of tracking hurricanes was developed in the mid-1950s, and steady improvements have beenmade over the years. In addition to reports from aircraft, geosynchronous weather satellites (since 1966) and ocean buoys tha...
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From Pride and Prejudice - anthology.
But why Mr Darcy same so often to the Parsonage, it was more difficult to understand. It could not be for society, as he frequently sat there ten minutes togetherwithout opening his lips; and when he did speak, it seemed the effect of necessity rather than of choice—a sacrifice to propriety, not a pleasure to himself. He seldomappeared really animated. Mrs Collins knew not what to make of him. Colonel Fitzwilliam's occasionally laughing at his stupidity, proved that he was generallydifferent, wh...
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Connecticut Yankee - anthology.
This missionary knight's name was La Cote Male Taile, and he said that this castle was the abode of Morgan le Fay, sister of King Arthur, and wife of King Uriens,monarch of a realm about as big as the District of Columbia—you could stand in the middle of it and throw bricks into the next kingdom. “Kings” and “Kingdoms”were as thick in Britain as they had been in little Palestine in Joshua's time, when people had to sleep with their knees pulled up because they couldn't stretch outwithout a passp...
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From Robinson Crusoe - anthology.
How strange a Chequer-Work of Providence is the Life of Man! and by what secret differing Springs are the Affections hurry'd about as differing Circumstancespresent! To Day we love what to Morrow we hate; to Day we seek what to Morrow we shun; to Day we desire what to Morrow we fear; nay even tremble at theApprehensions of; this was exemplify'd in me at this Time in the most lively Manner imaginable; for I whose only Affliction was, that I seem'd banished from humanSociety, that I was alone, cir...
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From The Adventures of Huckleberry Finn - anthology.
'Wherebouts?' says I. 'Down to Silas Phelps's place, two mile below here. He's a runaway nigger, and they've got him. Was you looking for him?' 'You bet I ain't! I run across him in the woods about an hour or two ago, and he said if I hollered he'd cut my livers out—and told me to lay down and stay where Iwas; and I done it. Been there ever since; afeard to come out.' 'Well,' he says, 'you needn't be afeard no more, becuz they've got him. He run off f'm down South, som'ers.' 'It'...
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World War II .
the Nazi-Soviet Pact was signed. In the part published the next day, Germany and the Soviet Union agreed not to go to war against each other. A secret protocol gaveStalin a free hand in Finland, Estonia, Latvia, eastern Poland, and eastern Romania. See also German-Soviet Nonaggression Pact. III MILITARY OPERATIONS In the early morning hours of September 1, 1939, the German armies marched into Poland. On September 3 the British and French surprised Hitler by declaring war onGermany, but they...
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Aztec Empire.
tribute to the empire in agricultural products, which were used to finance public projects. All able-bodied men owed military service to the empire. Citizens could also bedrafted to work on public lands or build temples, dikes, aqueducts, and roads. Although Aztec society had strict classes, a person’s status could change based on his or her contribution to society. Commoners could improve their rank, especially byperforming well in battle, and become prosperous landowners. Young people of some...
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Aztec Empire - USA History.
tribute to the empire in agricultural products, which were used to finance public projects. All able-bodied men owed military service to the empire. Citizens could also bedrafted to work on public lands or build temples, dikes, aqueducts, and roads. Although Aztec society had strict classes, a person’s status could change based on his or her contribution to society. Commoners could improve their rank, especially byperforming well in battle, and become prosperous landowners. Young people of some...
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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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Constitution of the United States.
chief executive should have the power to veto legislation, should be elected by Congress or the people, should be eligible to run for reelection, and should command thearmed forces. Some delegates even hoped for a limited monarchy. Not until September 8, more than three months after the convention started, did the final shape ofthe presidency emerge: a single leader, elected to a four-year term and eligible for reelection, with authority to veto bills enacted by Congress. The president was alsog...
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Constitution of the United States - U.
chief executive should have the power to veto legislation, should be elected by Congress or the people, should be eligible to run for reelection, and should command thearmed forces. Some delegates even hoped for a limited monarchy. Not until September 8, more than three months after the convention started, did the final shape ofthe presidency emerge: a single leader, elected to a four-year term and eligible for reelection, with authority to veto bills enacted by Congress. The president was alsog...
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Relativity - astronomy.
beta, for example, might be as large as 0.5, and the mass of the electron doubled. The mass of a rapidly moving electron could be easily determined by measuring thecurvature produced in its path by a magnetic field; the heavier the electron, the greater its inertia and the less the curvature produced by a given strength of field ( see Magnetism). Experimentation dramatically confirmed Einstein's prediction; the electron increased in mass by exactly the amount he predicted. Thus, the kinetic ener...
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Protests in the 1960s - U.
E Youth Culture Young people played an important role in the movements for social change during the 1960s. Numbers alone made them important; more than 76 million babies wereborn during the post-World War II “baby boom.” In addition, these young people spent more years in school and were more affluent than previous generations. In theearly 20th century, most young Americans had moved quickly from childhood to adulthood. In the 1920s only 1 in 5 Americans graduated from high school, and almostal...
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W. L. Mackenzie King.
I
INTRODUCTION
W. L. Mackenzie King (1874-1950), tenth prime
V SECOND TERM AS PRIME MINISTER By the election of 1925 most of the rifts in the Liberal Party were healed. Little had been achieved by King's government except for some tariff reduction and thereorganization of Canadian railroads, but no mistakes had been made. The real issue of the election was the personalities of the party leaders, King and the brilliant butarrogant Conservative, Arthur Meighen. The Conservatives swept English-speaking Canada, and they won 116 seats. The Liberals won 101, a...
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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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Feudalism
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INTRODUCTION
Feudalism, contractual system of political and military relationships existing among members of the nobility in Western Europe during the High Middle Ages.
lord”; thus, it was not rebellion for a subvassal to fight against his lord’s lord. In England, however, William the Conqueror and his successors required their vassals’vassals to take oaths of fealty to them. B Duties of a Vassal Military service in the field was basic to feudalism, but it was far from all that the vassal owed to his lord. When the lord had a castle, he might require his vassals togarrison it, a service called castle-guard. The lord also expected his vassals to attend his cour...
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Silk Road - History.
and high in value because they were carried on the backs of the limited number of camels in each caravan. Thus, of necessity they were luxury items, not bulky rawmaterials or essential goods for daily use. The oases and towns along the route, which were located in or near remote areas, profited from the Silk Road trade and reliedon it for their existence. The great empires of Persia, China, and Rome, however, could easily have survived without the commerce in luxury goods. V SPREAD OF RELIGION A...
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Iran-Iraq War - History.
The Iranian offensives of 1982 set a pattern that continued for the rest of the war. Exploiting their superiority in numbers, Iran sent its Revolutionary Guard on theattack, supported by regular military forces. Outnumbered Iraqi forces inflicted heavy losses on the Iranians but ultimately fell back. As soon as the initial Iranian thrusthad exhausted itself, however, the Iraqi army exploited Iranian disorganization and lack of equipment to retake much of the lost territory. As the war continued,...