359 résultats pour "usually"
- Lifehack
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Native Americans of Middle and South America.
A line that snakes across central Mexico near the Tropic of Cancer forms the northern boundary of Mesoamerica; north of this line rainfall sharply declines and theclimate is much drier. The ancient civilizations of Mesoamerica all arose and developed in the area between this line and the Guatemalan highlands far to the south. Richvolcanic soils are found throughout much of the region. A2 People and Languages Mesoamerica was a great melting pot, home to many peoples and interrelated cultures. In...
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Native Americans of North America.
addition to smallpox and measles, explorers and colonists brought a host of other diseases: bubonic plague, cholera, typhoid fever, scarlet fever, pleurisy, mumps,diphtheria, pneumonia, whooping cough, malaria, yellow fever, and various sexually transmitted infections. Despite the undisputed devastation wreaked on Indian populations after European contact, native populations showed enormous regional variability in their response todisease exposure. Some peoples survived and, in some cases, even...
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Native Americans of North America - Canadian History.
addition to smallpox and measles, explorers and colonists brought a host of other diseases: bubonic plague, cholera, typhoid fever, scarlet fever, pleurisy, mumps,diphtheria, pneumonia, whooping cough, malaria, yellow fever, and various sexually transmitted infections. Despite the undisputed devastation wreaked on Indian populations after European contact, native populations showed enormous regional variability in their response todisease exposure. Some peoples survived and, in some cases, even...
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Diseases of Animals.
infected animal. It may also spread in milk or in garbage that contains contaminated meat. Typical symptoms include blisters that appear on the mouth and feet;animals may become lame when their hooves degenerate. Canine distemper is a highly contagious disease caused by the paramyxovirus, which is transmitted in discharges from the nose and eyes. Symptoms begin with fever,malaise, and nasal and ocular discharges and may progress to convulsions and other nervous system disorders. Parvoviruses aff...
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Extinction (biology) - biology.
III ROLE OF MASS EXTINCTION IN EVOLUTION Historically biologists—most famous among them British naturalist Charles Darwin—assumed that extinction is the natural outcome of competition between newlyevolved, adaptively superior species and their older, more primitive ancestors. These scientists believed that newer, more highly evolved species simply drove less well-adapted species to extinction. That is, historically, extinction was thought to result from evolution. It was also thought that this...
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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...
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Health Care System in Canada.
With a few exceptions, provincial health plans cover all medically necessary services, so that patients need not pay directly for anything except so-called incidental costs.These incidental costs include items such as a patient’s private hospital room, unless it is specified by a physician, and transportation to the hospital. Provincial healthplans also do not cover some nonessential procedures, such as laser surgery for the eye, cosmetic surgery, procedures to reverse sterilization, and, in mos...
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Mesopotamian Art and Architecture
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INTRODUCTION
Mesopotamian Art and Architecture, the arts and buildings of the ancient Middle Eastern civilizations that developed in the area (now Iraq) between the Tigris and
Euphrates rivers from prehistory to the 6th century
BC.
arts. III EARLY DYNASTIC PERIOD Figures from Tell AsmarCreated around 2700 bc, these stone figures are from the city of Tell Asmar in what today is Iraq. From the Temple ofAbu, the statuettes stood in watchful prayer with the wide, staring eyes often found in Sumerian sculpture. The figuresare in the Iraq Museum, Baghdād, Iraq.Art Resource, NY The first historical epoch of Sumerian dominance lasted from about 3000 BC until about 2340 BC. While earlier architectural traditions continued, a ne...
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Stress (psychology).
blood flow is diverted from the internal organs and skin to the brain and muscles. Breathing speeds up, the pupils dilate, and perspiration increases. This reaction issometimes called the fight-or-flight response because it energizes the body to either confront or flee from a threat. Another part of the stress response involves the hypothalamus and the pituitary gland, parts of the brain that are important in regulating hormones and many otherbodily functions. In times of stress, the hypothal...
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Kuwait (country) - country.
Oil revenues have allowed Kuwait to build an extensive educational system, yielding a literacy rate of 84 percent. Public school is free and compulsory from the age of 6to 13, and several private schools also teach this age group. Kuwait University (founded in 1966) is also free and offers programs in a wide range of professional andscientific fields at several campuses. Both the extensive library system at Kuwait University and the collection at Kuwait National Museum (1957) were heavily damage...
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Radioactivity
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INTRODUCTION
Marie Curie
Working with her husband, Pierre Curie, French physicist Marie Curie discovered the radioactive elements polonium and
radium in 1898.
Rutherford when he allowed an alpha-emitting substance to decay near an evacuated thin-glass vessel. The alpha particles were able to penetrate the glass and werethen trapped in the vessel, and within a few days the presence of elemental helium was demonstrated by use of a spectroscope. Beta particles were subsequentlyshown to be electrons, and gamma rays to consist of electromagnetic radiation of the same nature as X rays but of considerably greater energy. A The Nuclear Hypothesis Rutherford...
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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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Children's Literature
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INTRODUCTION
Kate Greenaway's May Day
The delicate skill and graceful simplicity of English artist Kate Greenaway's illustrations delighted children and impressed
thinkers, including art critic John Ruskin.
With the development of vernacular literature, particularly after the invention of printing, more children's books appeared. The publications of the first English printer,William Caxton, included the Book of Curtesye (1477), a collection of rhymes that sets forth rules of conduct for a “goodly chylde.” Eight years later Caxton printed Le Morte d'Arthur (1469-1470; The Death of Arthur ) by English translator and compiler Sir Thomas Malory, which became the basis for later treatments of the A...
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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...
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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...
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Space Shuttle - astronomy.
The two SRBs, with their combined thrust of some 26 million newtons (about 5.8 million lb), provide most of the power for the first two minutes of flight. The SRBs takethe space shuttle to an altitude of 45 km (28 mi) and a speed of 4,973 km/h (3,094 mph) before they separate and fall back into the ocean to be retrieved,refurbished, and prepared for another flight. After the boosters fall away, the three main engines continue to provide thrust. These engines are clustered at the rear end of the...
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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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Volcano.
before eruption. Very violent explosive eruptions are called Plinian eruptions, after Roman naturalist Pliny the Elder. These eruptions can last for several hours to daysand eject a large amount of pyroclastic material. Some volcanoes can produce much more energetic eruptions that eject materials farther from the vents because oftheir andesitic and dacitic composition. Andesitic and dacitic lava is generally thicker than basaltic lava. Stiff lava generally produces more-explosive eruptions. B No...
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Bahrain - country.
A Religion Almost all Bahrainis and the majority of nonnatives are followers of Islam (Muslims). About 70 percent of all native Bahrainis belong to the Shia branch of Islam, whilethe remainder, including the ruling al-Khalifa clan, are adherents of the Sunni branch. Non-Muslims, including Hindus, Buddhists, Christians, and Jews, account for 15percent of the total population. High unemployment among the Shia population has caused considerable discontent on the part of this group toward the Sunni...
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Carbon - chemistry.
Graphite is black and slippery and conducts electricity. In graphite, the atoms form planar, or flat, layers. Each layer is made up of rings containing six carbon atoms.The rings are linked to each other in a structure that resembles the hexagonal mesh of chicken wire. Each atom has three sigma bonds (with 120° between any two ofthe bonds) and belongs to three neighboring rings. The fourth electron of each atom becomes part of an extensive pi bond system. Graphite conducts electricity,because th...
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Map - Geography.
Often only southeast slopes are hachured or shaded, giving somewhat the effect of a bird's-eye view of the area illuminated by light from the northwest. Shadings orcarefully drawn hachures, neither of which give elevations, are more easily interpreted than contour lines and are sometimes used in conjunction with them for greaterclarity. IV MAP PROJECTIONS For the representation of the entire surface of the earth without any kind of distortion, a map must have a spherical surface; a map of this...
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International Law.
merchants), modernized the rights of neutrals during maritime war, and required blockades to be effective. The Declaration of Paris also initiated the practice of allowingnations other than the original signatories to accede (become a party to) to an agreement. In 1864 a conference convened in Geneva, Switzerland, at the invitation of the Swiss government. The conference approved a convention for the proper treatment ofwounded soldiers on the battlefield and the protection of medical personnel;...
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Accounting and Bookkeeping.
The proliferation of mandated notes that accompany financial statements is a particularly visible example. Such notes disclose information that is not already included inthe body of the financial statement. One of the very first notes identifies the accounting methods adopted when acceptable alternative methods also exist, or when theunique nature of the company's business justifies an otherwise unconventional approach. The notes also disclose information about lease commitments, contingent liab...
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Money.
A Early Monetary Regulations In the American colonies, coins of almost every European country circulated, with the Spanish dollar predominating. Because of the scarcity of coins, the colonists alsoused various primitive mediums of exchange, such as bullets, tobacco, and animal skins. Many of the colonies issued paper money that circulated at varying rates ofdiscount. The first unified currency consisted of the notes issued by the Continental Congress to finance the American Revolution. These no...
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Turtle.
Turtles use their jaws to cut and handle food. Instead of teeth, a turtle’s upper and lower jaws are covered by horny ridges, similar to a bird’s beak. Meat-eating turtlescommonly have knife-sharp ridges for slicing through their prey. Plant-eating turtles often have ridges with serrated edges that help them cut through tough plants.Turtles use their tongues in swallowing food, but unlike many other reptiles, such as chameleons, they cannot stick out their tongues to capture food. C Limb Structu...
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Turtle - biology.
Turtles use their jaws to cut and handle food. Instead of teeth, a turtle’s upper and lower jaws are covered by horny ridges, similar to a bird’s beak. Meat-eating turtlescommonly have knife-sharp ridges for slicing through their prey. Plant-eating turtles often have ridges with serrated edges that help them cut through tough plants.Turtles use their tongues in swallowing food, but unlike many other reptiles, such as chameleons, they cannot stick out their tongues to capture food. C Limb Structu...
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Elephant - biology.
B Trunk An elephant's nose and upper lip are combined in a long, limber trunk, an exceptionally supple appendage with an estimated 150,000 muscles. The versatile trunk actslike a hand for grasping low-growing shrubs and other food and placing it into the mouth; an arm for breaking off tree branches; or a snorkel for breathing when theelephant's body is submerged. Elephants also use their trunks to suck up water and squirt it into their mouths for drinking or over their bodies for bathing. Nostr...
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Mountain Climbing.
teeth on one side, and a straight, flat, metal blade called an adze on the other. Ice axes have many uses. One of the most common is to help the climber stay balanced on steep slopes. The climber swings the axe with a short, quick movement to lodge the pick in snow or ice, creating a secure anchor. If a climber should slip and beginsliding down a snowfield, a self-arrest can be performed by turning face down on the snow and burying the pick in the snow surface. The climber’s weight over the...
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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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Fishing.
directly to the spool and turns the spool one rotation at a time. C Fishing Lines Fishing lines serve as the link between the angler’s reel and the lure or bait. The most popular line used for sportfishing is monofilament nylon line, which is strong anddurable and has a certain amount of stretch, which helps when an angler sets the hook. The line comes in a variety of strengths, from 2-pound test to more than 100-pound test. (Pound test is the amount of pressure that can be put on a line before...
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Rain Forest.
dropped into the heart of the forest by helicopters. Suspended from the crane’s long, movable arm is a large gondola that functions as a mobile treetop laboratory.Moving from tree to tree, forest researchers collect specimens, conduct experiments, and observe life in the canopy frontier. The highest stratum of the rain forest is made up of the emergent trees, those individuals that stick up above the forest canopy. Emergents, which do not form acontinuous layer, are usually the giants of the for...
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Welfare.
industrializing societies. Governments typically financed social insurance programs with tax funds and direct levies on the wages of potential recipients. Social insurancereplaced part of incomes lost when workers became disabled, were laid off, or had reached an age that forced them out of the labor market. Later, governments of Germany, France, Belgium, Sweden, and other countries developed forms of social insurance that provided population-wide, or universal,coverage. Such forms included chil...
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Greek Mythology.
world in search of her; as a result, fertility left the earth. Zeus commanded Hades to release Persephone, but Hades had cunningly given her a pomegranate seed toeat. Having consumed food from the underworld, Persephone was obliged to return below the earth for part of each year. Her return from the underworld each yearmeant the revival of nature and the beginning of spring. This myth was told especially in connection with the Eleusinian Mysteries, sacred rituals observed in the Greektown of Ele...
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American Literature: Drama
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INTRODUCTION
American Literature: Drama, literature intended for performance, written by Americans in the English language.
American plays, while still a minority, began to appear in the theater repertory in the 19th century. Although American plays were still styled after British models, theirsubject matter came to be based on specifically American incidents or themes. In the United States as in Britain, many plays reflected the influence of romanticism , a European literary and artistic movement. Melodrama, with its outpourings of emotion, was the most prevalent dramatic form in the 19th century. Gothic melodramas...
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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...
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Delaware - geography.
D Climate Delaware has generally hot and humid summers and mild winters. D1 Temperature In July, average daytime temperatures are usually in the upper 20°s to lower 30°sC (80°sF) or even higher. But because summer nights tend to be cooler than thedays, July averages are about 24°C (about 75°F). In addition, onshore sea breezes can reduce daytime temperatures along the coast by 3 to 6 Celsius degrees (5 to 10Fahrenheit degrees). January averages range from -1°C (31°F) at Newark, in the north, t...
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Delaware - USA History.
D Climate Delaware has generally hot and humid summers and mild winters. D1 Temperature In July, average daytime temperatures are usually in the upper 20°s to lower 30°sC (80°sF) or even higher. But because summer nights tend to be cooler than thedays, July averages are about 24°C (about 75°F). In addition, onshore sea breezes can reduce daytime temperatures along the coast by 3 to 6 Celsius degrees (5 to 10Fahrenheit degrees). January averages range from -1°C (31°F) at Newark, in the north, t...
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Connecticut - geography.
The state’s shoreline, when all the bays and inlets are taken into account, has a total length of 995 km (618 mi). The coastline is deeply indented by long estuaries androcky inlets, and there are many sandy beaches and stretches of tidal marsh. There are several good harbors along the coast, the most important of which is at NewHaven. A few small islands lie offshore in Long Island Sound. D Climate Connecticut has long, hot summers and cold winters. The climate does not vary greatly from place...
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Connecticut - USA History.
The state’s shoreline, when all the bays and inlets are taken into account, has a total length of 995 km (618 mi). The coastline is deeply indented by long estuaries androcky inlets, and there are many sandy beaches and stretches of tidal marsh. There are several good harbors along the coast, the most important of which is at NewHaven. A few small islands lie offshore in Long Island Sound. D Climate Connecticut has long, hot summers and cold winters. The climate does not vary greatly from place...
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London (England) - geography.
In the northern part of the West End is Bloomsbury, the city’s traditional intellectual center, with its concentration of bookshops and homes of writers and academics. Inthe early 20th century a number of famous writers, critics, and artists who lived here became known as the Bloomsbury Group. Here, too, is the British Museum, one ofLondon’s chief tourist attractions. Nearby is the giant complex of the University of London, whose various colleges and departments have taken over much ofBloomsbury...
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New Brunswick - Geography.
Grand Lake, the largest lake in New Brunswick, is in the lowlands, east of Fredericton. Most other lakes are located in the northern and southwestern parts of NewBrunswick. D Climate New Brunswick has a continental climate that is moderated by maritime influences in the coastal areas. As a result, coastal regions are slightly warmer in the winter andslightly cooler in the summer than are interior regions. Annual temperature variations are large, with the January mean usually at least 25 to 28°C...
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New Brunswick - Canadian History.
Grand Lake, the largest lake in New Brunswick, is in the lowlands, east of Fredericton. Most other lakes are located in the northern and southwestern parts of NewBrunswick. D Climate New Brunswick has a continental climate that is moderated by maritime influences in the coastal areas. As a result, coastal regions are slightly warmer in the winter andslightly cooler in the summer than are interior regions. Annual temperature variations are large, with the January mean usually at least 25 to 28°C...
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Earth (planet).
Milky Way to complete one revolution around the Galaxy’s center. Earth’s axis of rotation is inclined (tilted) 23.5° relative to its plane of revolution around the Sun. This inclination of the axis creates the seasons and causes the height of the Sun in the sky at noon to increase and decrease as the seasons change. The Northern Hemisphere receives the most energy from the Sun when it is tiltedtoward the Sun. This orientation corresponds to summer in the Northern Hemisphere and winter in the S...
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Earth (planet) - astronomy.
Milky Way to complete one revolution around the Galaxy’s center. Earth’s axis of rotation is inclined (tilted) 23.5° relative to its plane of revolution around the Sun. This inclination of the axis creates the seasons and causes the height of the Sun in the sky at noon to increase and decrease as the seasons change. The Northern Hemisphere receives the most energy from the Sun when it is tiltedtoward the Sun. This orientation corresponds to summer in the Northern Hemisphere and winter in the S...
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Colorado - geography.
Although the rivers of Colorado are navigable only by small boats, they are important as a source of irrigation water for use in Colorado and adjoining states. However,the water level of the rivers fluctuates seasonally and from year to year. The level is generally low in winter and high in spring and summer, during the runoff of meltedsnow from the mountains. Colorado has no large lakes of natural origin, but there are numerous small lakes in the mountains. The largest bodies of water in Colora...
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Colorado - USA History.
Although the rivers of Colorado are navigable only by small boats, they are important as a source of irrigation water for use in Colorado and adjoining states. However,the water level of the rivers fluctuates seasonally and from year to year. The level is generally low in winter and high in spring and summer, during the runoff of meltedsnow from the mountains. Colorado has no large lakes of natural origin, but there are numerous small lakes in the mountains. The largest bodies of water in Colora...
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Fascism.
values as coming before a radical political transformation. Others argue that a radical political transformation will then be followed by a change in values. Fascists claimthat the nation has entered a dangerous age of mediocrity, weakness, and decline. They are convinced that through their timely action they can save the nation fromitself. Fascists may assert the need to take drastic action against a nation's 'inner' enemies. Fascists promise that with their help the national crisis will end an...
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Montana - geography.
(191 sq mi), is Montana’s largest lake, and the largest natural freshwater lake in the contiguous states west of the Mississippi River. C Climate Climatic regions in Montana coincide roughly with the two major physiographic regions. In western Montana, as compared with the eastern plains area, winters tend tobe milder while summers are cooler. Precipitation is more evenly distributed throughout the year in the west, and it is cloudier and somewhat more humid in all seasons.In addition, the grow...
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Montana - USA History.
(191 sq mi), is Montana’s largest lake, and the largest natural freshwater lake in the contiguous states west of the Mississippi River. C Climate Climatic regions in Montana coincide roughly with the two major physiographic regions. In western Montana, as compared with the eastern plains area, winters tend tobe milder while summers are cooler. Precipitation is more evenly distributed throughout the year in the west, and it is cloudier and somewhat more humid in all seasons.In addition, the grow...