806 résultats pour "much"

• Cheetah - biology.

  animals such as zebras. Unlike most cats, cheetahs hunt during the day, when lions and hyenas that compete with them for prey are less likely to be active. Still,scientists in Tanzania have observed that cheetahs lose 10 to 13 percent of their kills to lions and hyenas. Alerted by the panic of a gazelle herd or by the circling ofvultures, lions and hyenas close in and easily drive the more timid cheetah away from a fresh kill. A cheetah usually stalks prey to within about 10 m (about 33 ft) and...

• Anthropology.

  humans, such as tools, pottery, and buildings) and human fossils (preserved bones). They also examine past environments to understand how natural forces, such as climate and available food, shaped the development of human culture. Some archaeologists study cultures that existed before the development of writing, a time knownas prehistory . The archaeological study of periods of human evolution up to the first development of agriculture, about 10,000 years ago, is also called paleoanthropology....

• Egypt - country.

  Egypt has a wide variety of mineral deposits, some of which, such as gold and red granite, have been exploited since ancient times. The chief mineral resource ofcontemporary value is petroleum, found mainly in the Red Sea coastal region, at Al ‘Alamayn (El ‘Alamein) on the Mediterranean, and on the Sinai Peninsula. Otherminerals include phosphates, manganese, iron ore, and uranium. Natural gas is also extracted. D Plants and Animals The vegetation of Egypt is confined largely to the Nile Delta,...

• Native American Art I INTRODUCTION Native American Art, the visual works crafted by indigenous people of North America, starting after their arrival on the continent thousands of years ago and continuing until the present.

  artists in the Ohio area cut delicate flat forms from sheets of mica in the shape of birds, human figures, and large hands. They also carved quite natural-looking birdsand animals on stone platform pipes. These figures sat on the pipe’s flat base, or platform, and on some pipes they were part of the pipe bowl. Prominent people ofthese cultures were buried with a wealth of ornaments, such as jewelry of shells and copper, and headdresses elaborated with animal forms. The period of Mississippian cu...

• 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,...

• Abraham Lincoln I INTRODUCTION Abraham Lincoln (1809-1865), 16th president of the United States (1861-1865) and one of the great leaders in American history.

  fence in 4 hectares (10 acres) to grow corn. Then he hired out to neighbors, helping them to split rails. That year, Lincoln attended a political rally and was persuaded tospeak on behalf of a local candidate. It was his first political speech. A witness recalled that Lincoln “was frightened but got warmed up and made the best speech of theday.” In 1831 Lincoln made a second trip to New Orleans. He was hired, along with his stepbrother and a cousin, by Denton Offutt, a Kentucky trader and specul...

• Abraham Lincoln.

  fence in 4 hectares (10 acres) to grow corn. Then he hired out to neighbors, helping them to split rails. That year, Lincoln attended a political rally and was persuaded tospeak on behalf of a local candidate. It was his first political speech. A witness recalled that Lincoln “was frightened but got warmed up and made the best speech of theday.” In 1831 Lincoln made a second trip to New Orleans. He was hired, along with his stepbrother and a cousin, by Denton Offutt, a Kentucky trader and specul...

• Abraham Lincoln

  fence in 4 hectares (10 acres) to grow corn. Then he hired out to neighbors, helping them to split rails. That year, Lincoln attended a political rally and was persuaded tospeak on behalf of a local candidate. It was his first political speech. A witness recalled that Lincoln “was frightened but got warmed up and made the best speech of theday.” In 1831 Lincoln made a second trip to New Orleans. He was hired, along with his stepbrother and a cousin, by Denton Offutt, a Kentucky trader and specul...

• Abraham Lincoln - USA History.

  fence in 4 hectares (10 acres) to grow corn. Then he hired out to neighbors, helping them to split rails. That year, Lincoln attended a political rally and was persuaded tospeak on behalf of a local candidate. It was his first political speech. A witness recalled that Lincoln “was frightened but got warmed up and made the best speech of theday.” In 1831 Lincoln made a second trip to New Orleans. He was hired, along with his stepbrother and a cousin, by Denton Offutt, a Kentucky trader and specul...

• Michelangelo I INTRODUCTION Michelangelo (1475-1564), Italian painter, sculptor, architect, and poet whose artistic accomplishments exerted a tremendous influence on his contemporaries and on subsequent European art.

  (17 ft) tall, was carved from a block of stone that another sculptor had left unfinished. Michelangelo drew on the classical tradition in depicting David as a nude,standing with his weight on one leg, the other leg at rest ( see contrapposto). This pose suggests impending movement, and the entire sculpture shows tense waiting, as David sizes up his enemy and considers his course of action. While David reveals Michelangelo's expert knowledge of anatomy (he had been dissecting corpses for about...

• Michelangelo.

  (17 ft) tall, was carved from a block of stone that another sculptor had left unfinished. Michelangelo drew on the classical tradition in depicting David as a nude,standing with his weight on one leg, the other leg at rest ( see contrapposto). This pose suggests impending movement, and the entire sculpture shows tense waiting, as David sizes up his enemy and considers his course of action. While David reveals Michelangelo's expert knowledge of anatomy (he had been dissecting corpses for about...

• On the road

• 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...

• Plant - biology.

  B1 Vacuoles Vacuoles are membrane-bound cavities filled with cell sap, which is made up mostly of water containing various dissolved sugars, salts, and other chemicals. B2 Plastids Plastids are types of organelles, structures that carry out specialized functions in the cell. Three kinds of plastids are important here. Chloroplasts contain chlorophyllsand carotenoid pigments; they are the site of photosynthesis, the process in which light energy from the sun is fixed as chemical energy in the b...

• Prince Edward Island - Geography.

  hectares (109 acres) each. In 2006 there were 1,700 farms, of which the average size was 148 hectares (366 acres). In 2005 the total farm cash receipts were C$510million. The most important agricultural products in terms of value include potatoes, milk and cream, cattle and calves, hogs, tobacco, vegetables, eggs, hens andchickens, and furs. For the most part the island’s agriculture is diversified, rather than specialized, because of the lack of a large urban industrial population within easy r...

• Prince Edward Island - Canadian History.

  hectares (109 acres) each. In 2006 there were 1,700 farms, of which the average size was 148 hectares (366 acres). In 2005 the total farm cash receipts were C$510million. The most important agricultural products in terms of value include potatoes, milk and cream, cattle and calves, hogs, tobacco, vegetables, eggs, hens andchickens, and furs. For the most part the island’s agriculture is diversified, rather than specialized, because of the lack of a large urban industrial population within easy r...

• Frog (animal).

  which means that their body temperature depends on the temperature of the surrounding environment. Few species can tolerate temperatures below 4°C (40°F) orabove 40°C (104°F), and many species can survive only within a narrower range of temperatures. In addition, frogs’ thin, moist skin offers little protection againstwater loss, and when on land the animals must guard against drying out. Many frogs are active at night because temperatures are cooler and humidity is higher thanduring the day. In...

• Frog (animal) - biology.

  which means that their body temperature depends on the temperature of the surrounding environment. Few species can tolerate temperatures below 4°C (40°F) orabove 40°C (104°F), and many species can survive only within a narrower range of temperatures. In addition, frogs’ thin, moist skin offers little protection againstwater loss, and when on land the animals must guard against drying out. Many frogs are active at night because temperatures are cooler and humidity is higher thanduring the day. In...

• The Souls of Black Folk by W.

  in amused contempt and pity. One ever feels his two-ness,—an American, a Negro; two souls, two thoughts, two unreconciled strivings; two warring ideals in onedark body, whose dogged strength alone keeps it from being torn asunder. The history of the American Negro is the history of this strife—this longing to attain self-conscious manhood, to merge his double self into a better and truer self. Inthis merging he wishes neither of the older selves to be lost. He would not Africanize America, f...

• Iranian Art and Architecture I 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...

• Océanos y oceanografía - ciencias de la naturaleza.

  El océano contiene el 97% del agua de la Tierra; en la atmósfera está el 0,001%. Los procesos que intercambian y transforman el agua en vapor, en líquido o en sólido sonfundamentales para el clima y para la propia vida. El agua es una de las sustancias más comunes, pero tiene algunas propiedades físicas y químicas inusuales. Es uno de los pocos líquidos naturales y puede encontrarse enlas tres fases: vapor de agua, agua líquida y hielo sólido. Tiene un calor específico y un calor latente grandes...

• Pyramids (Egypt) - geography.

  limestone debris left over from the construction work. When the workers had completed the pyramid and installed the pyramidion, or cap stone, ramps still covered the surface of the pyramid. As the workers dismantled the ramps from the top down, they slowly exposed the pyramid’s stone surface, which stonemasons smoothed and polished. When the ramp was gone, the pyramid wasdisplayed in its full majesty. B Interior The interior of the Great Pyramid is complex, with a series of passages leading t...

• Pyramids (Egypt) - History.

  limestone debris left over from the construction work. When the workers had completed the pyramid and installed the pyramidion, or cap stone, ramps still covered the surface of the pyramid. As the workers dismantled the ramps from the top down, they slowly exposed the pyramid’s stone surface, which stonemasons smoothed and polished. When the ramp was gone, the pyramid wasdisplayed in its full majesty. B Interior The interior of the Great Pyramid is complex, with a series of passages leading t...

• Republican Party.

  the reaction to the depression that the Republican Party controlled Congress for only 4 of the 48 years between 1932 and 1980. The Republicans did win the presidencyfour times during that period—in 1952, 1956, 1968, and 1972—when the Democratic Party split or when some unusual combination of circumstances occurred. Fromthe 1930s through the 1970s, however, the Democratic Party was the dominant party in the United States. The response of the Republicans to this new situation was confusion, anger,...

• Chess.

  There are two standard methods of recording chess moves: the algebraic system and the descriptive system. In both systems, the pieces are designated by capitalinitials: K for king, Q for queen, R for rook, B for bishop, and N for knight. The initial P for pawn is used in the descriptive system only. Castling is noted as either 0-0(“short” castling on the king’s side) or 0-0-0 (“long” castling on the queen’s side). Each square is part of both a file and a rank, and in the algebraic system, that u...

• White House - geography.

  Each Thanksgiving, the pardoning of the turkey takes place in the Rose Garden. This ceremony of rescuing a turkey and sending it to a petting zoo began during HarryTruman’s term, although Abraham Lincoln is said to have set a precedent by sparing his son’s pet turkey from the oven. III INSIDE THE WHITE HOUSE A large complex is needed for the many activities that take place at the White House. The White House has 132 rooms, 4 dining rooms, 35 bathrooms, 8 staircases, 3elevators, a clinic, a den...

• From Bulfinch's Mythology: Cupid and Psyche - anthology.

  waters, and fast by, a magnificent palace whose august front impressed the spectator that it was not the work of mortal hands, but the happy retreat of some god.Drawn by admiration and wonder, she approached the building and ventured to enter. Every object she met filled her with pleasure and amazement. Golden pillarssupported the vaulted roof, and the walls were enriched with carvings and paintings representing beasts of the chase and rural scenes, adapted to delight the eye of thebeholder. Pro...

• 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...

• 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’...

• Labor Unions in Canada - Canadian History.

  job. Before collective bargaining begins, workers elect a bargaining committee. The bargaining committee determines the workers’ demands and strategy innegotiations with the employer. Local unions usually are part of national or international unions. These national and international unions employ a staff for organizing workers at the local level, doingresearch, educating union members about labor and political matters, and working with local union leaders. Unions hold regular conventions of dele...

• Inorganic Chemistry - chemistry.

  two electrically charged plates (positively charged top plate and negatively charged bottom plate). By measuring the difference in how fast these electron-laden oildrops fell when the metal plates were charged and uncharged, Millikan was able to calculate the total charge on each oil drop. Because each measurement was a wholenumber multiple of -1.60 × 10 -19 coulombs, Millikan concluded this was the charge carried by a single electron. Using Thomson’s electron charge-to-mass ratio, Millikan then...

• Shark - biology.

  Sharks have two-chambered hearts that are relatively small compared to the rest of their bodies. Blood flows from the heart to the gills, where it collects oxygen fromwater and then distributes it to the other organs and tissues. The small heart produces weak blood pressure, and many sharks must swim continuously to create themuscular contractions needed to circulate blood throughout their bodies. Most sharks are cold-blooded—that is, they do not generate heat by digesting food. Instead, the bod...

• Capital Punishment.

  deterrent effect. Capital punishment advocates note that because the death penalty is reserved for the most aggravated murders, the deterrent effect of capitalpunishment on such crimes may not be apparent in data on homicide rates in general. Supporters also urge that the conflicting results of various studies indicate thatthe deterrent effect of the death penalty cannot not be proven or disproven with any certainty. They maintain that in the absence of conclusive proof that the threat ofexecuti...

• Maya Civilization.

  destruction was directed mostly at temples in the ceremonial precincts; it had little or no impact on the economy or population of a city as a whole. Some city-states didoccasionally conquer others, but this was not a common occurrence until very late in the Classic period when lowland civilization had begun to disintegrate. Until thattime, the most common pattern of Maya warfare seems to have consisted of raids employing rapid attacks and retreats by relatively small numbers of warriors, most o...

• Maya Civilization - History.

  destruction was directed mostly at temples in the ceremonial precincts; it had little or no impact on the economy or population of a city as a whole. Some city-states didoccasionally conquer others, but this was not a common occurrence until very late in the Classic period when lowland civilization had begun to disintegrate. Until thattime, the most common pattern of Maya warfare seems to have consisted of raids employing rapid attacks and retreats by relatively small numbers of warriors, most o...

• Buddhism.

  Although never actually denying the existence of the gods, Buddhism denies them any special role. Their lives in heaven are long and pleasurable, but they are in thesame predicament as other creatures, being subject eventually to death and further rebirth in lower states of existence. They are not creators of the universe or incontrol of human destiny, and Buddhism denies the value of prayer and sacrifice to them. Of the possible modes of rebirth, human existence is preferable, because thedeitie...

• Telecommunications.

  commonly referred to as wireless communications, use technologies such as cordless telephones, cellular radio telephones, pagers, and satellites. Wirelesscommunications offer increased mobility and flexibility. In the future some experts believe that wireless devices will also offer high-speed Internet access. C Wires and Cables Wires and cables were the original medium for telecommunications and are still the primary means for telephone connections. Wireline transmission evolved fromtelegraph...

• Japan - country.

  island’s fertile soils support agriculture and provide the vast majority of Japan’s pasturelands. In addition, Hokkaidō contains coal deposits, and the cold currents off itsshores supply cold-water fish. Winters are long and harsh, so most of Hokkaid ō is lightly settled, housing about 5 percent of Japan’s population on approximately 20 percent of its land area. However,its snowy winters and unspoiled natural beauty attract many skiers and tourists. Hokkaid ō is thought of as Japan’s northern fr...

• 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...

• 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...

• History of Chemistry - chemistry.

  even better distillation apparatus than the Arabs had made and to condense the more volatile products of distillation. Among the important products obtained in thisway were alcohol and the mineral acids: nitric, aqua regia (a mixture of nitric and hydrochloric), sulfuric, and hydrochloric. Many new reactions could be carried outusing these powerful reagents. Word of the Chinese discovery of nitrates and the manufacture of gunpowder also came to the West through the Arabs. The Chinese atfirst use...

• Census.

  Prior to any census, a census agency must develop an accurate list of addresses and maps to ensure that everyone is counted. The U.S. Census Bureau obtainsaddresses primarily from the United States Postal Service and from previous census address lists. It also works closely with state, local, and tribal governments tocompile accurate lists. Finally, census agencies often conduct an extensive marketing campaign before Census Day to remind the general population about theimportance of responding t...

• Belarus - country.

  In the last complete census conducted in the Soviet Union in 1989, the population of Belarus was 10,151,806; a 2008 estimate was 9,685,768, giving the country apopulation density of 47 persons per sq km (121 per sq mi). The most notable demographic trend since the 1950s has been the steady migration of the population fromthe villages to urban centers, and the correspondent aging of the population remaining in the rural areas. In 1959 urban residents accounted for 31 percent of thepopulation; in...

• Library (institution).

  rooms, special galleries for exhibitions, auditoriums for lectures or concerts, computer rooms, children’s rooms, photocopy rooms, and classrooms. A3 Lending Materials As part of their mission to provide information resources to the community, public libraries allow users to borrow items from their collections for limited amounts of time.To be eligible to borrow public library materials, a user must register her or his name, address, and other basic information with the local library’s circulat...

• Ghana - country.

  times of depressed cacao prices, Ghana has significantly increased exports of timber to generate needed revenue. In 1988 Ghana initiated a conservation plan called the Forest Resource Management Project. In 1989 Ghana restricted the export of 18 tree species, and in 1994 thecountry banned the export of raw logs. About 4.8 percent (1997) of the country’s land is officially protected, but illegal logging threatens Ghana’s remaining forests. Deforestation, overgrazing, and periodic drought have led...

• Christmas.

  The new custom of Christmas gift giving allowed the marketplace to exert an unprecedented influence on holiday celebrations. Commercial innovations such asdepartment stores and mass advertising further expanded the custom of exchanging Christmas gifts. Seasonal retail sales helped fuel the economy, causing merchantsand advertisers to become some of the season’s most ardent promoters. Many holiday celebrants regretted these changes, however, and began voicing the nowcommon lament that Christmas h...

• Segregation in the United States - U.

  acts of discrimination. Writing for the court, Justice Joseph Bradley declared: “When a man has emerged from slavery, and by the aid of beneficent legislation ... theremust be some stage in the progress of his elevation when he takes the rank of a mere citizen, and ceases to be the special favorite of the laws, and when his rights as acitizen, or a man, are to be protected in the ordinary modes by which other men’s rights are protected.” Rather than being the “special favorites” of the law, blac...

• Egyptian Art and Architecture - USA History.

  The kings of the 1st Dynasty (2920 BC-2770 BC) were buried in the cemetery of their ancestors at Abydos in southern Egypt. Their burial sites were built of mud brick (bricks baked in the sun) and consisted of two parts: a tomb in the desert where the king was buried, and a rectangular funerary enclosure at the desert's edge, whererituals were performed. A pair of stone slabs called stelae marked the tombs and bore the name of the royal occupant. In the 2nd Dynasty (2770 BC-2649 BC), most r...

• Saskatchewan (province) - Geography.

  The length of the frost-free season varies within the province. In the southwest, particularly in the valley lands along the South Saskatchewan River, the frost-freeperiod ranges from 150 to 160 days. Regina enjoys about 123 frost-free days, and Saskatoon has about 111. The far north has only from 85 to 95 frost-free days. One important characteristic of Saskatchewan’s climate is the great variability in temperature and precipitation from year to year, which is often critical for agriculture.The...

• Saskatchewan (province) - Canadian History.

  The length of the frost-free season varies within the province. In the southwest, particularly in the valley lands along the South Saskatchewan River, the frost-freeperiod ranges from 150 to 160 days. Regina enjoys about 123 frost-free days, and Saskatoon has about 111. The far north has only from 85 to 95 frost-free days. One important characteristic of Saskatchewan’s climate is the great variability in temperature and precipitation from year to year, which is often critical for agriculture.The...