24 résultats pour "unknown"
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Algebra
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INTRODUCTION
Algebra, branch of mathematics in which symbols (usually letters) represent unknown numbers in mathematical equations.
B Order of Operations and Grouping Algebra relies on an established sequence for performing arithmetic operations. This ensures that everyone who executes a string of operations arrives at the sameanswer. Multiplication is performed first, then division, followed by addition, then subtraction. For example: 1 + 2 · 3 equals 7 because 2 and 3 are multiplied first and then added to 1. Exponents and roots have even higher priority than multiplication: 3 · 2 2 = 3 · 4 = 12 Grouping symbols override...
- The idea of progress in Address Unknown
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Lewis and Clark Expedition.
took a small detachment into present-day north central Montana, thinking that the course of the Marias River might provide an American claim to fur-rich country inwhat is now the Canadian province of Alberta. In August the groups reunited on the Missouri River, near the mouth of the Yellowstone. They arrived in St. Louis onSeptember 23, 1806. C Relations with the Native Americans and Spanish The Lewis and Clark Expedition made a journey through the homelands of native people. What American expl...
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Lewis and Clark Expedition - explorer.
took a small detachment into present-day north central Montana, thinking that the course of the Marias River might provide an American claim to fur-rich country inwhat is now the Canadian province of Alberta. In August the groups reunited on the Missouri River, near the mouth of the Yellowstone. They arrived in St. Louis onSeptember 23, 1806. C Relations with the Native Americans and Spanish The Lewis and Clark Expedition made a journey through the homelands of native people. What American expl...
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Christopher Columbus
I
INTRODUCTION
Christopher Columbus (1451-1506), Italian-born Spanish navigator who sailed west across the Atlantic Ocean in search of a route to Asia but achieved fame by making
landfall in the Americas instead.
explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...
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Christopher Columbus.
explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...
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Christopher Columbus.
explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...
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Christopher Columbus - explorer.
explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...
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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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Aboriginal Australians - History.
Until Europeans began to settle in Australia in 1788, the Aboriginal way of life was supported by hunting, gathering, and fishing. Like other hunting and gatheringpeoples, Aboriginal people had an extremely detailed knowledge of their environment, especially plant ecology and animal behavior. The deep connection betweenAboriginal people and the natural world influenced every part of their culture, including their food gathering, tools, trade, religion, art, music, language, and socialorganizatio...
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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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Camel - biology.
of water in the stomach or hump as was once commonly believed. Unlike other mammals, however, the camel can survive as long as three weeks without drinking,depending on the water content of its food. It can survive a water loss of about 40 percent of its normal body weight. In comparison, a loss of 15 percent is usually fatalfor humans. Camels can go without water due to several unique adaptations to their environment. The camel conserves more water in its body than any other mammal. It excretes...
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Human Disease.
disease can be transmitted through food infected with mutated proteins. B Spread of Infectious Disease Some pathogens are spread from one person to another by direct contact. They leave the first person through body openings, mucous membranes, and skin wounds,and they enter the second person through similar channels. For example, the viruses that cause respiratory diseases such as influenza and the common cold are spreadin moisture droplets when an infected person coughs or sneezes. A hand that...
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Antarctica - Geography.
The maximum area of sea ice surrounding Antarctica each winter varies from year to year. A marked decline during the 1970s appears to have reversed in more recentdecades, except in the Antarctic Peninsula area. This area has lost almost 40 percent of its sea ice since the start of the 1980s. Sea ice is important to marine life. Krillfeed on algae that live under the sea ice and are released when the ice melts in spring and summer. In turn, many marine animals feed on krill. Emperor penguinsbreed...
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Australia - country.
itself forms most of the border between New South Wales and Victoria. Considerable lengths of the Murray, Darling, and Murrumbidgee rivers are navigable during thewet seasons. The central plains region, also known as the Channel Country, is interlaced by a network of rivers. During the rainy season these rivers flood the low-lying countryside,but in dry months they become merely a series of water holes. The Victoria, Daly, and Roper rivers drain a section of the Northern Territory. In Queensland...
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Australia - Geography.
itself forms most of the border between New South Wales and Victoria. Considerable lengths of the Murray, Darling, and Murrumbidgee rivers are navigable during thewet seasons. The central plains region, also known as the Channel Country, is interlaced by a network of rivers. During the rainy season these rivers flood the low-lying countryside,but in dry months they become merely a series of water holes. The Victoria, Daly, and Roper rivers drain a section of the Northern Territory. In Queensland...
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- Gestion de l'information touristique devoir 3 CNED Bts tourisme
- Medee
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From The Red Badge of Courage - anthology.
The youth put forth anxious arms to assist him, but the tall soldier went firmly on as if propelled. Since the youth's arrival as a guardian for his friend, the otherwounded men had ceased to display much interest. They occupied themselves again in dragging their own tragedies toward the rear. Suddenly, as the two friends marched on, the tall soldier seemed to be overcome by a terror. His face turned to a semblance of gray paste. He clutched the youth's armand looked all about him, as if dre...
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Galaxy - astronomy.
Astronomers have obtained images of young galaxies using the Keck Telescope in Hawaii and the Hubble Space Telescope, which resides in an orbit high above Earth’satmosphere and thus avoids atmospheric interference. Photos from the HST show galaxies that are as far as 13 billion light-years away from Earth, which means theyformed soon after the universe formed about 13.7 billion years ago. The galaxies appear to be spherical in shape, and may be early precursors of elliptical and spiralgalaxies....
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Bacteria - biology.
A2 b Bacterial Killers Some dramatic infectious diseases result from exposure to bacteria that are not part of our normal bacterial community. Cholera, one of the world’s deadliest diseasestoday, is caused by the bacterium Vibrio cholerae . Cholera is spread in water and food contaminated with the bacteria, and by people who have the disease. After entering the body, the cholera bacteria grow in the intestines, often along the surface of the intestinal wall, where they secrete a toxin (poiso...
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Mars (planet) - astronomy.
The Martian core is probably much like Earth’s, consisting mostly of iron, with a small amount of nickel. If other light elements, particularly sulfur, exist there as well, thecore may be larger than presently thought. From studying Earth’s magnetic field and core, scientists theorize that the motions of the liquid rock in Earth’s core generateits magnetic field. Mars does not have a significant magnetic field, so scientists believe that Mars’s core is probably solid. However, spacecraft data in...