134 résultats pour "keep"
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Honey Bee - biology.
B Reproduction and Development The queen controls the sex of her offspring. When an egg passes from her ovary to her oviduct, the queen determines whether the egg is fertilized with sperm from thespermatheca. A fertilized egg develops into a female honey bee, either worker or queen, and an unfertilized egg becomes a male honey bee, or drone. The queen lays the eggs that will develop into more queens in specially constructed downward-pointing, peanut-shaped cells, in which the egg adheres to the...
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Excerpt from Mansfield Park - anthology.
arranged round the other. It was a fine arrangement for Henry Crawford, who was close to Fanny, and with his hands full of business, having two persons' cards tomanage as well as his own—for though it was impossible for Fanny not to feel herself mistress of the rules of the game in three minutes, he had yet to inspirit herplay, sharpen her avarice, and harden her heart, which, especially in any competition with William, was a work of some difficulty; and as for Lady Bertram, he mustcontinue in c...
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Artificial Satellite - astronomy.
The first stage of a multistage rocket consists of rocket engines that provide a huge amount of force, or thrust. The first stage lifts the entire launch vehicle—with itsload of fuel, the rocket body, and the satellite—off the launch pad and into the first part of the flight. After its engines use all their fuel, the first stage portion of therocket separates from the rest of the launch vehicle and falls to Earth. The second stage then ignites, providing the energy necessary to lift the satellit...
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Extrasolar Planets - astronomy.
When a planet passes in a front of the star it orbits—an event called a transit—it causes a small dip in the brightness of the star. Measuring the slight change in thebrightness can be used not only to directly detect a planet, but to determine its size and orbit. However, the planet needs to orbit in a plane that lies in a telescope’sline of sight on the star. Despite long odds, Earth-based telescopes have detected and studied a few exoplanets using this method. The first space telescope design...
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Panama Canal - Geography.
The size of ships using the Panama Canal has steadily increased. About 27 percent of the vessels that use the canal are built to the maximum dimensions that can passthrough it (a category called “Panamax”). This has prompted further widening of Gaillard Cut, so that the larger Panamax vessels may transit safely. However, some ofthe world’s commercial and military ships are too large for the canal. Since the 1940s, new U.S. battleships and aircraft carriers have been built exceeding the canal’sdi...
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Marketing.
Where advertising reaches a mass audience, personal or direct selling focuses on one customer at a time. That kind of individual attention makes direct sellingexpensive, but it also makes it effective. As the costs of personal selling have risen, the utilization of salespeople has changed. Simple transactions are completed byclerks. Salespeople are now used primarily where the products are complex and require detailed explanation, customized application, or careful negotiation over priceand paym...
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Animation
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INTRODUCTION
Finding Nemo
A clown fish named Marlin, left, and his friend Dory search for Marlin's son in the computer-animated feature film Finding
Nemo (2003).
Animator at WorkAnimators use computers for every part of the animation process, from creating a storyboard (a scene-by-sceneillustration of the plot) to imitating camera movement. This animator is creating a scene for the motion picture Antz(1998).C. Lepetit/Liaison Agency If an animator is basing the animation project on drawings, one of the most common animation techniques, he or she will first create a series of rough sketches thatoften will be filmed in a pencil test (simple line drawings...
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Snake (reptile).
in their heads that conduct sound. They are able to hear low-frequency sounds and to sense vibrations that travel through the ground or water. The majority of snakeshave good eyesight, especially for detecting moving objects, although most burrowing snakes can only distinguish between light and dark. Pit vipers, boas, and pythons have an unusual adaptation for detecting warm-blooded prey and predators. On the heads of these snakes are small pits lined with cellsthat are extremely sensitive to he...
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Tiger - biology.
have a simple digestive system designed to process meat so that the nutrients can be readily absorbed into the bloodstream. With the exception of white tigers, which have blue eyes, all tigers have yellow eyes. Tigers mainly use vision to find prey. Although tigers see about as well as humansduring the day, their large eye openings gather more light than do human eyes, making tiger night vision far superior to that of humans. In addition, a special structurein the tiger’s eye, called the tapetu...
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Ronald Reagan.
deposed shah of Iran to enter the United States for medical treatment, a group of Iranian revolutionaries stormed the U.S. Embassy in Tehrān and held 53 Americansas hostages. United States media publicized the plight of the hostages and Carter’s failure to win their release. They were eventually released in January 1981, on theday of Reagan’s inauguration. The contrast between the television personalities of the two candidates was also very important. Carter’s stiff, nervous manner had never bee...
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Ronald Reagan - USA History.
deposed shah of Iran to enter the United States for medical treatment, a group of Iranian revolutionaries stormed the U.S. Embassy in Tehrān and held 53 Americansas hostages. United States media publicized the plight of the hostages and Carter’s failure to win their release. They were eventually released in January 1981, on theday of Reagan’s inauguration. The contrast between the television personalities of the two candidates was also very important. Carter’s stiff, nervous manner had never bee...
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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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Tennis.
and interpret rules. The head official on the court, called the chair umpire, sits on a tall chair at one end of the net. A varying number of line judges sit around the courtbeyond the path of the players. Line judges determine whether serves and shots are good or out. A net-cord judge may be employed to determine when a ball touchesthe top of the net, and a foot-fault judge may watch for that specific infraction. In the 1980s electronic devices began to be used in some professional tournaments...
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Cosmology - astronomy.
In 1917 American scientist Harlow Shapley measured the distance to several groups of stars known as globular clusters. He measured these distances by using amethod developed in 1912 by American astronomer Henrietta Leavitt. Leavitt’s method relates distance to variations in brightness of Cepheid variables, a class of starsthat vary periodically in brightness. Shapley’s distance measurements showed that the clusters were centered around a point far from the Sun. The arrangement of theclusters was...
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National Parks and Preserves.
Some ibex raised in Italy’s 700 sq km (220 sq mi) Gran Paradiso National Park (1922) were transferred to aid herd restoration elsewhere in the country. Switzerlandreturned lynx to Swiss National Park to keep red deer populations in check. The growth of national parks also enabled many European countries to restore forests thathad given way to industrialization by the early 20th century. Africa’s wildlife was hunted heavily from the late 19th century well into the 20th century. By 1920 big-game h...
- Midnighters
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Canadian Parliament.
government’s legislative program. Members of Commons can also present a motion in response to the Budget Speech, which reviews the government’s economicrecord, taxation, and expenditure plans, and to Supply Motions, which concern budgets for individual departments. If a majority of MPs support a no-confidence motion,the government must resign. Also, if Parliament rejects a significant government proposal, the government is expected to resign and request the governor-general to call an election....
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World Energy Supply.
In the 1990s, oil production by non-OPEC countries remained strong and production by OPEC countries rebounded. The result at the end of the 20th century was aworld oil surplus and prices (when adjusted for inflation) that were lower than in 1972. Experts are uncertain about future oil supplies and prices. Low prices have spurred greater oil consumption, and experts question how long world petroleum reservescan keep pace with increased demand. Many of the world’s leading petroleum geologists beli...
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Basketball.
rebound. Play continues as the teams score and possession changes. A time-out, when the game is stopped for a certain amount of time, allows coaches to instructplayers or to develop a new game strategy. A Offense Playing offense is perhaps the most prominent part of playing basketball, as it allows players to demonstrate and improve upon individual skills necessary to beingsuccessful. Many of basketball's best players have exceptional talents on offense. Basic offensive skills are passing, ball...
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North Dakota - geography.
Bismarck, the growing season averages 134 days, as the average date of the last killing frost is May 11 and that of the first killing frost is September 22. The length ofthe growing season drops to about 110 days in the northerly reaches of the state. The long periods of summer sunshine at this latitude, providing as much as 16 hoursof daylight in summer, help crops to mature quickly, thus compensating somewhat for the relatively short growing season. Temperatures in the north are, on the averag...
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North Dakota - USA History.
Bismarck, the growing season averages 134 days, as the average date of the last killing frost is May 11 and that of the first killing frost is September 22. The length ofthe growing season drops to about 110 days in the northerly reaches of the state. The long periods of summer sunshine at this latitude, providing as much as 16 hoursof daylight in summer, help crops to mature quickly, thus compensating somewhat for the relatively short growing season. Temperatures in the north are, on the averag...
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Thomas Jefferson
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INTRODUCTION
Thomas Jefferson (1743-1826), third president of the United States (1801-1809) and author of the Declaration of Independence.
Jefferson was a poor speaker, but his literary talents made him a highly valued member of committees when resolutions and other public papers were drafted. Heemerged as the recognized author of the patriot cause in Virginia and indeed in the whole of the colonies. Jefferson's first public paper, however, was considered toostiff and formal, and it was rewritten. The paper was a response to the greeting of the new governor, Lord Botetourt, to the General Assembly. Jefferson, who nevertook criticis...
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Thomas Jefferson.
Jefferson was a poor speaker, but his literary talents made him a highly valued member of committees when resolutions and other public papers were drafted. Heemerged as the recognized author of the patriot cause in Virginia and indeed in the whole of the colonies. Jefferson's first public paper, however, was considered toostiff and formal, and it was rewritten. The paper was a response to the greeting of the new governor, Lord Botetourt, to the General Assembly. Jefferson, who nevertook criticis...
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Thomas Jefferson
Jefferson was a poor speaker, but his literary talents made him a highly valued member of committees when resolutions and other public papers were drafted. Heemerged as the recognized author of the patriot cause in Virginia and indeed in the whole of the colonies. Jefferson's first public paper, however, was considered toostiff and formal, and it was rewritten. The paper was a response to the greeting of the new governor, Lord Botetourt, to the General Assembly. Jefferson, who nevertook criticis...
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Thomas Jefferson - USA History.
Jefferson was a poor speaker, but his literary talents made him a highly valued member of committees when resolutions and other public papers were drafted. Heemerged as the recognized author of the patriot cause in Virginia and indeed in the whole of the colonies. Jefferson's first public paper, however, was considered toostiff and formal, and it was rewritten. The paper was a response to the greeting of the new governor, Lord Botetourt, to the General Assembly. Jefferson, who nevertook criticis...
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American Literature: Poetry
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INTRODUCTION
Phyllis McGinley
American poet and author Phyllis McGinley composed light, witty verse, much of which deals with family life.
Taylor, a poet of great technical skill, wrote powerful meditative poems in which he tested himself morally and sought to identify and root out sinful tendencies. In“God's Determinations Touching His Elect” (written 1680?), one of Taylor’s most important works, he celebrates God's power in the triumph of good over evil in thehuman soul. All of Taylor’s poetry and much of Bradstreet’s served generally personal ends, and their audience often consisted of themselves and their family andclosest frie...
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Bill Clinton.
When Arkansas governor David Pryor ran for the U.S. Senate in 1978, Clinton ran for governor. He promised to improve the state’s schools and highways and toimprove economic conditions so that more jobs would be created. At that time, the average income of people in Arkansas ranked 49th among the 50 states. Clinton woneasily, receiving 60 percent of the vote against four opponents in the Democratic primary election and 63 percent against the Republican candidate, Lynn Lowe, in thegeneral election...
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Bill Clinton - USA History.
When Arkansas governor David Pryor ran for the U.S. Senate in 1978, Clinton ran for governor. He promised to improve the state’s schools and highways and toimprove economic conditions so that more jobs would be created. At that time, the average income of people in Arkansas ranked 49th among the 50 states. Clinton woneasily, receiving 60 percent of the vote against four opponents in the Democratic primary election and 63 percent against the Republican candidate, Lynn Lowe, in thegeneral election...
- The way in which companies frame themselves, their products and their clients
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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...
- On the road
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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...