337 résultats pour "must"

• Museum.

  History museums are dedicated to promoting a greater appreciation and knowledge of history and its importance to understanding the present and anticipating thefuture. They range from historic sites and small historic house museums to large, encyclopedic institutions such as the Smithsonian’s National Museum of AmericanHistory in Washington, D.C. Many cities and states have historical societies that operate museums or historic sites. History museums usually collect a wide range ofobjects, includi...

• Fiji Islands - country.

  the early 1990s. Fishing is done mainly at a subsistence level, but commercial fishing is increasing. The country also receives income from the sale of licenses to foreignvessels to fish in Fiji’s exclusive economic zone. Industry, including mining, manufacturing, and construction, employs 34 percent of Fiji’s wage earners and, in 2006, contributed 26 percent of GDP. The governmentinstituted tax-free incentives in 1988 that created a flourishing garment industry. Ready-made garments are now the...

• Library of Congress.

  manuscripts, books, and films. The Digital Library’s eventual goal is to make available 80 million items from the Library of Congress’s collection that are not easilyavailable elsewhere. V ORGANIZATION AND FUNDING The librarian of Congress serves as the director of the institution. Tradition, politics, and strong personalities have shaped the function of this office. Although the Libraryof Congress was established in 1800, the office of librarian was not created until passage of a law in 1802....

• 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...

• Air Pollution.

  Several pollutants attack the ozone layer. Chief among them is the class of chemicals known as chlorofluorocarbons (CFCs), formerly used as refrigerants (notably in airconditioners), as agents in several manufacturing processes, and as propellants in spray cans. CFC molecules are virtually indestructible until they reach thestratosphere. Here, intense ultraviolet radiation breaks the CFC molecules apart, releasing the chlorine atoms they contain. These chlorine atoms begin reacting withozone, br...

• Ballet I INTRODUCTION Tchaikovsky's The Nutcracker The Nutcracker is a classic ballet with music by Peter Ilyich Tchaikovsky.

  Joffrey Ballet SchoolTraining for classical ballet dancers must begin when the students are very young. Here, teacher Dorothy Lister workswith her pre-ballet class of six-year-olds at the Joffrey Ballet School. These students are learning the five basic positions ofclassical ballet.Susan Kunklin/Photo Researchers, Inc. Different systems of ballet training have evolved, named after countries (Russia, France) or teachers (Italian dancer Enrico Cecchetti, Danish choreographer AugustBournonville). T...

• 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...

• Supernova - astronomy.

  The term hypernova has been proposed for an extremely massive core-collapse supernova—possibly more than 100 times the mass of the Sun. A hypernova is thought to form a black hole. Just before it explodes, a hypernova may release a huge burst of gamma rays in a jet from the rotating black hole at its center. These jets mayexplain the so-called long gamma-ray bursts detected by astronomers. According to some researchers, massive stars with over 40 solar masses may sometimescollapse directly int...

• Flower - biology.

  insects. The sepals unfurl as the flower opens and often resemble small green leaves at the flower’s base. In some flowers, the sepals are colorful and work with thepetals to attract pollinators. E Variations in Structure Like virtually all forms in nature, flowers display many variations in their structure. Most flowers have all four whorls—pistil, stamens, petals, and sepals. Botanists callthese complete flowers. But some flowers are incomplete, meaning they lack one or more whorls. Incomplet...

• Birding - biology.

  swallows, and rock doves nest on buildings in cities, towns, and farms. The chimney swift has abandoned hollow trees for chimneys as a nest site in urban areas.Mallards and Canada geese—once exclusively wild, migratory species—now live year-round in the open spaces found in city parks and golf courses. Nearly all purplemartins, a songbird species that once used the abandoned nests of woodpeckers or the natural cavities of cliffs or dead trees, now live primarily in structures specificallyconstru...

• Literary Criticism I INTRODUCTION Literary Criticism, discussion of literature, including description, analysis, interpretation, and evaluation of literary works.

  IV THE 17TH AND 18TH CENTURIES The climate of criticism changed with the arrival on the literary scene of such giants as Miguel de Cervantes, Lope de Vega, and Pedro Calderòn in Spain; WilliamShakespeare, Ben Jonson, and John Milton in England; and Pierre Corneille, Jean Baptiste Racine, and Molière in France. Most of these writers specialized or excelled indrama, and consequently the so-called battle of the ancients and moderns—the critical comparison of Greek and Roman authors with more rece...

• Cyprus - country.

  40,000 cubic meters (1.4 million cubic feet) of salt water into fresh water per day, opened at Dhekelia in 1997, and a second larger plant opened at Larnaca in 2001. III PEOPLE OF CYPRUS The combined population of the Greek and Turkish sectors (2008 estimate) is 792,604. The overall population density is 86 persons per sq km (222 per sq mi). About69 percent of the island’s inhabitants live in urban areas. Greek-speaking Cypriots make up approximately 85 percent of the population. About 12 perc...

• Introduction to Hamlet

• Drug. I INTRODUCTION Drug, substance that affects the function of living cells, used

  normalizing chemical activity in the emotional centers of the brain. Antianxiety drugs, also referred to as tranquilizers, treat anxiety by decreasing the activity in theanxiety centers of the brain. Sedative-hypnotic drugs are used both as sedatives to reduce anxiety and as hypnotics to induce sleep. Sedative-hypnotic drugs act by reducing brain-cell activity.Stimulant drugs, on the other hand, increase neuronal (nerve cell) activity and reduce fatigue and appetite. Analgesic drugs reduce pain...

• 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...

• 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...

• 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...

• 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...

• John Adams.

  the British authorities. The royal governor, aware of Adams's ability and growing influence, offered him the post of advocate general in the admiralty court. Adams declined the appointment,recognizing it as a bribe to bring him over to the side of the British government. A3 Adams and the Boston Massacre Adams generally supported the popular resistance to the British government, but he did not condone violence or mob action. Adams was greatly disturbed by theBoston Massacre of 1770, an incident...

• John Adams

  the British authorities. The royal governor, aware of Adams's ability and growing influence, offered him the post of advocate general in the admiralty court. Adams declined the appointment,recognizing it as a bribe to bring him over to the side of the British government. A3 Adams and the Boston Massacre Adams generally supported the popular resistance to the British government, but he did not condone violence or mob action. Adams was greatly disturbed by theBoston Massacre of 1770, an incident...

• John Adams - U.

  the British authorities. The royal governor, aware of Adams's ability and growing influence, offered him the post of advocate general in the admiralty court. Adams declined the appointment,recognizing it as a bribe to bring him over to the side of the British government. A3 Adams and the Boston Massacre Adams generally supported the popular resistance to the British government, but he did not condone violence or mob action. Adams was greatly disturbed by theBoston Massacre of 1770, an incident...

• Midnighters

• On the road

• Comet - astronomy.

  may exceed the planet Jupiter in size, however. Observations from telescopes on Earth and in space indicate that most of the gases in the coma and tail of a comet are fragmentary molecules, or radicals, of the mostcommon elements in space: hydrogen, carbon, nitrogen, and oxygen. The radicals, for example, of CH, NH, and OH may be broken away from the stable molecules CH 4 (methane), NH 3 (ammonia), and H 2O (water), which may exist as ices or more complex, very cold compounds in the nucleus. Al...

• Ant - biology.

  The workers of many ant species carry a stinger within the hind end of the gaster. These ants use the stinger to defend against their enemies. In some species, workerants lack a stinger but use the tip of their gaster to squirt or dab poison at other small animals and when fighting battles with other ants, fending off predators, or killinginsects or other animals that they use as food. III PHYSIOLOGY Ants have a rigid, external skeleton called an exoskeleton that gives the soft, inner body its...

• Johann Sebastian Bach.

  from his duties, and even tossed him into jail for “too obstinately requesting his dismissal.” But after several weeks the duke saw it was of no use and let him go. E Köthen: 1717-1723 Bach’s new employer, Leopold, loved and understood music and could play the violin, viola da gamba, and harpsichord as well as sing bass. The prince held Bach in highregard and stood as godfather for his seventh child. Bach, in turn, named the child Leopold August in his employer’s honor. Bach later said that the...

• The Alchimist

• The way in which companies frame themselves, their products and their clients

• Saudi Arabia - country.

  C Natural Resources Some of the world’s largest oil and natural gas fields lie beneath Saudi Arabia and its offshore waters, representing the country’s most economically important naturalresource. In 2007 Saudi Arabia’s oil reserves were estimated at 264 billion barrels. Before the discovery and exploitation of these reserves in the mid-20th century,Saudi Arabia was one of the poorest countries in the world. Its relatively small population subsisted in a harsh environment with little agricultur...

• Excerpt from Persuasion - anthology.

  “Yes, dear ma'am,” said Mrs. Croft, “or an uncertain engagement, an engagement which may be long. To begin without knowing that at such a time there will be themeans of marrying, I hold to be very unsafe and unwise, and what I think all parents should prevent as far as they can.” Anne found an unexpected interest here. She felt its application to herself, felt it in a nervous thrill all over her; and at the same moment that her eyes instinctivelyglanced towards the distant table, Captain Wen...

• 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...

• New Mexico - geography.

  New Mexico’s major river is the Río Grande, originating in southern Colorado, and flowing southward for 760 km (470 mi) through the state. Between the San LuisValley and Española Valley the river flows in a deep canyon known as the Río Grande Gorge; then, below White Rock Canyon, it flows through several valleys containingagricultural land. Most of the water of the Río Grande is used to irrigate these valleys. The Río Grande’s waterflow in New Mexico is extremely low. One of the major tributarie...

• New Mexico - USA History.

  New Mexico’s major river is the Río Grande, originating in southern Colorado, and flowing southward for 760 km (470 mi) through the state. Between the San LuisValley and Española Valley the river flows in a deep canyon known as the Río Grande Gorge; then, below White Rock Canyon, it flows through several valleys containingagricultural land. Most of the water of the Río Grande is used to irrigate these valleys. The Río Grande’s waterflow in New Mexico is extremely low. One of the major tributarie...

• Arizona - geography.

  of the Mogollon Rim, the Little Colorado draws very little water from a relatively large watershed, usually containing a mere trickle of water in its riverbed. The ColoradoRiver’s principal tributary is the Gila River, which flows all the way across the southern part of the state from New Mexico to the California border. From the mountainsand plateaus of central Arizona, the Gila River receives the Salt, Agua Fria, and Hassayampa rivers. The Salt River is itself fed by the Verde River. The Gila...

• Arizona - USA History.

  of the Mogollon Rim, the Little Colorado draws very little water from a relatively large watershed, usually containing a mere trickle of water in its riverbed. The ColoradoRiver’s principal tributary is the Gila River, which flows all the way across the southern part of the state from New Mexico to the California border. From the mountainsand plateaus of central Arizona, the Gila River receives the Salt, Agua Fria, and Hassayampa rivers. The Salt River is itself fed by the Verde River. The Gila...

• African American History - U.

  In their day-to-day lives, slaves and servants shared similar grievances and frequently formed alliances. Advertisements seeking the return of slaves and servants whohad run away together filled colonial newspapers. When a slave named Charles escaped in 1740, the Pennsylvania Gazette reported that two white servants, a 'Scotch man' and an Englishman, escaped with him. Sometimes interracial alliances involved violence. During Bacon's Rebellion in 1676, slaves and servants took up armsagainst Na...