494 résultats pour "low"
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Asia - History.
Borneo, the world’s third largest island after Greenland and New Guinea. To the southeast is the Timor Sea separating the Asian island of Timor from the Australiancontinent. The Indian subcontinent is flanked by the Bay of Bengal on the east and the Arabian Sea on the west. The island of Sri Lanka and the much smaller Maldives andNicobar Islands trail away to the south. The Arabian Sea’s Gulf of Aden, the Red Sea, the Mediterranean Sea, and the Black Sea form an arc along the western rim of Asia...
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Automobile.
Electric motors have been used to power automobiles since the late 1800s. Electric power supplied by batteries runs the motor, which rotates a driveshaft, the shaftthat transmits engine power to the axles. Commercial electric car models for specialized purposes were available in the 1980s. General Motors Corporation introduced amass-production all-electric car in the mid-1990s. Automobiles that combine two or more types of engines are called hybrids. A typical hybrid is an electric motor with ba...
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Sweden - country.
mi) and is Sweden’s second largest lake, after Vänern. The two lakes, together with several smaller lakes, rivers, and canals, form an internal water route called theGöta Canal. Built in the early 19th century, the Göta Canal extends for about 386 km (about 240 mi) and provides a scenic transportation link between the Baltic Sea,at Stockholm, and the Kattegat. Sweden’s other large lakes in the district include Mälaren, Hjälmaren, and the famously picturesque Siljan. D Climate Although one-seven...
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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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Washington (state) - geography.
The crest of the Cascade Range divides Washington into two distinct climatic regions. The area west of the Cascades, which is exposed throughout the year to rain-bearing winds from the Pacific Ocean, has a temperate marine type of climate that is characterized by mild wet winters and cool summers. The Cascades prevent themoist air blowing in from the Pacific from reaching eastern Washington. The Rocky Mountains on the eastern border also represent a climatic barrier. As a result, thesevere winte...
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Washington (state) - USA History.
The crest of the Cascade Range divides Washington into two distinct climatic regions. The area west of the Cascades, which is exposed throughout the year to rain-bearing winds from the Pacific Ocean, has a temperate marine type of climate that is characterized by mild wet winters and cool summers. The Cascades prevent themoist air blowing in from the Pacific from reaching eastern Washington. The Rocky Mountains on the eastern border also represent a climatic barrier. As a result, thesevere winte...
- Camille PISSARRO: LOWER NORWOOD, LONDRES, EFFET DE NEIGE
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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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Jupiter (planet) - astronomy.
Beneath the supercritical fluid zone, the pressure reaches 3 million Earth atmospheres. At this depth, the atoms collide so frequently and violently that the hydrogenatoms are ionized—that is, the negatively charged electrons are stripped away from the positively charged protons of the hydrogen nuclei. This ionization results in asea of electrically charged particles that resembles a liquid metal and gives rise to Jupiter’s magnetic field. This liquid metallic hydrogen zone is 30,000 to 40,000 k...
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Sydney (Australia) - geography.
blocks in the eastern suburbs and around railway stations elsewhere; and homes on large lots in the outer suburbs, especially those to the northwest. For publichousing, the state government built a number of high-rise apartment blocks in run-down inner suburbs after World War II (1939-1945). These housing projects weresoon deemed unsuccessful and were discontinued because they fostered crime and other social problems. More recently, public housing has taken the form of separateor semidetached ho...
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Oklahoma - geography.
portion and the Panhandle are classified as a steppe, where precipitation, typically 250 to 500 mm (10 to 20 in), is the controlling characteristic. January is usually the coldest month with an average of about 3°C (38°F) and extremes from -33°C (-27°F), the lowest ever recorded, to 33°C (92°F). Summer arelong and hot with temperatures in the upper 30°s C (lower 100°s F) common from May until September across the state. The growing season varies from less than 180days in the western Panhandle to...
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Oklahoma - USA History.
portion and the Panhandle are classified as a steppe, where precipitation, typically 250 to 500 mm (10 to 20 in), is the controlling characteristic. January is usually the coldest month with an average of about 3°C (38°F) and extremes from -33°C (-27°F), the lowest ever recorded, to 33°C (92°F). Summer arelong and hot with temperatures in the upper 30°s C (lower 100°s F) common from May until September across the state. The growing season varies from less than 180days in the western Panhandle to...
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Idaho - geography.
Idaho-Montana state line in the southern part of the Bitterroot Mountains. Consequently, nearly all the rivers in the state drain toward the Pacific. Most of Idaho lieswithin the drainage basin of the Columbia River system. The Snake River, which is the chief river in southern and central Idaho, follows a crescent-shaped course forabout 790 km (about 490 mi) across southern Idaho. It then swings northward along the Idaho state line and joins the Columbia River in Washington. Major tributariesof...
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Idaho - USA History.
Idaho-Montana state line in the southern part of the Bitterroot Mountains. Consequently, nearly all the rivers in the state drain toward the Pacific. Most of Idaho lieswithin the drainage basin of the Columbia River system. The Snake River, which is the chief river in southern and central Idaho, follows a crescent-shaped course forabout 790 km (about 490 mi) across southern Idaho. It then swings northward along the Idaho state line and joins the Columbia River in Washington. Major tributariesof...
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George Bush.
1986 it was folded into Harken Energy Corporation, another Texas petroleum company. Bush served as a consultant and a member of Harken’s board of directors. In 1987 Bush relocated his family to Washington, D.C., to assist his father in his bid to become president. He worked as a campaign adviser at his father’s nationalcampaign headquarters, serving as a liaison to the media and to conservative and Christian leaders. He was a trusted confidant of his father and mother, whosometimes dispatched Bu...
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George Bush - USA History.
1986 it was folded into Harken Energy Corporation, another Texas petroleum company. Bush served as a consultant and a member of Harken’s board of directors. In 1987 Bush relocated his family to Washington, D.C., to assist his father in his bid to become president. He worked as a campaign adviser at his father’s nationalcampaign headquarters, serving as a liaison to the media and to conservative and Christian leaders. He was a trusted confidant of his father and mother, whosometimes dispatched Bu...
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Judicial Branch.
courts or from state courts, and a handful come from other parts of the Court’s jurisdiction ( see Supreme Court of the United States: Selecting Cases). The Court typically issues written decisions in fewer than a hundred cases a year. All cases are heard and decided by the entire Court, except in rare cases when a justice choosesnot to participate because of a conflict of interest or other potential prejudicial interest in a case. As with all other federal judges, members of the Supreme Court a...
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Yangtze - Geography.
A Agriculture and Industry Today about 400 million people, or about one-third of the population of China, live in the Yangtze Basin. Many are engaged in agriculture. The basin contributes nearlyhalf of China’s crop production, although only one-quarter of the basin is arable. The most fertile areas for farming are the Sichuan Basin, the plains between theYangtze and its tributary the Han, and the plains of the lower basin. In all about 40 percent of the cereals, more than 30 percent of the cott...
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Ear.
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INTRODUCTION
Ear, organ of hearing and balance. Only vertebrates, or animals
line or rotates in any direction. Each canal also contains sensory areas with sensory hair cells that project into a cone-shaped cap of gelatin. Two of the semicircularcanals are in a vertical position and are used to detect vertical movement, such as jumping or falling. The third canal is horizontal and detects horizontal movement,such as turning or spinning. The action of the canals depends on the inertia of the fluid inside. When the motion of the body changes, the fluid lags behind, causing...
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Supreme Court of Canada.
whether the leave to appeal will be granted and the case heard by the Court. The Court has no specified criteria by which it determines whether to grant leave, and the Court does not give reasons for its decision. The key factor appears to be acase’s degree of national importance. Other factors might include the impact of uncertainty in the challenged law, the case’s appropriateness for developing the law torespond to changing social needs, and the presence of a split decision at the court of ap...
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Czech Republic - country.
enforcement of environmental regulations. Environmental considerations have also led some government officials to promote nuclear energy as a key source of powerfor the country’s future. The Czech Republic produces most of its energy by burning domestic coal. Much of the coal burned is low quality with a high ash and sulfur content—a key componentof acid rain—producing high levels of air pollution. Forests in the Czech Republic are among the most seriously affected by acid rain in all of Europe....
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Electricity
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INTRODUCTION
Electricity, one of the basic forms of energy.
electrons in the neutral object are attracted to the positive object. Some of these electrons flow to the side of the neutral object that is nearest to the positive object.This side of the neutral object accumulates electrons and becomes negatively charged. Because electrons leave the far side of the neutral object while its protonsremain stationary, that side becomes positively charged. Since the negatively charged side of the neutral object is closest to the positive object, the attraction bet...
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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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Democratic Republic of the Congo - country.
Except in the high elevations, the country’s climate is very hot and humid. The average annual temperature in the low central area is about 27°C (about 80°F).Temperatures are considerably higher in February, the hottest month. At altitudes above about 1,500 m (about 5,000 ft) the average annual temperature is about 19°C(about 66°F). Average annual rainfall is about 1,500 mm (about 60 in) in the north and about 1,300 mm (about 50 in) in the south. Frequent heavy rains occur fromApril to November...
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Alberta - Geography.
C Climate Except for the mountain areas, summers throughout the province are quite warm. Winters are long and extremely cold. In July, average daily temperatures range fromabout 16°C (about 60°F) along the northern boundary to about 21°C (about 70°F) in the south. In the extreme southeastern section of the province, temperatures of43°C (110°F) have been recorded. In January, average daily temperatures range from about -14°C (about 6°F) at Grande Prairie to about -9°C (about 16°F) atCalgary. Tem...
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Alberta - Canadian History.
C Climate Except for the mountain areas, summers throughout the province are quite warm. Winters are long and extremely cold. In July, average daily temperatures range fromabout 16°C (about 60°F) along the northern boundary to about 21°C (about 70°F) in the south. In the extreme southeastern section of the province, temperatures of43°C (110°F) have been recorded. In January, average daily temperatures range from about -14°C (about 6°F) at Grande Prairie to about -9°C (about 16°F) atCalgary. Tem...
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Rhode Island - geography.
C (73° F). Along the northern state line, the January mean temperature is about 1° C (about 2° F) colder than in Warwick in January. Along the ocean coast, theJanuary mean temperature is -1° C (30° F). Warm season temperatures are also influenced by the ocean and bay, so temperatures are usually cooler along the coastthan in the interior. The difference tends to be greatest in spring and early summer. Winter temperatures in Rhode Island are usually above -7° C (20° F), buttemperatures colder by...
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Rhode Island - USA History.
C (73° F). Along the northern state line, the January mean temperature is about 1° C (about 2° F) colder than in Warwick in January. Along the ocean coast, theJanuary mean temperature is -1° C (30° F). Warm season temperatures are also influenced by the ocean and bay, so temperatures are usually cooler along the coastthan in the interior. The difference tends to be greatest in spring and early summer. Winter temperatures in Rhode Island are usually above -7° C (20° F), buttemperatures colder by...
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Evolution - biology.
genetic diversity to extinction. Sexual reproduction ensures that the genes in a population are rearranged in each generation, a process termed recombination. Although the combinations of genes inindividuals change with each new generation, the gene frequency, or ratio of different alleles in the entire population, remains relatively constant if no evolutionaryforces act on the population. One such force is the introduction of new genes into the genetic material of the population, or gene pool...
- Lowe (sir Hudson), 1769-1844, né à Galway, général britannique.
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Arctic - geography.
B Rivers and Lakes Low precipitation is characteristic of the Arctic, so large and elaborate river and lake systems are rare. In many places, however, permafrost (permanently frozen subsoil)restricts the downward drainage of meltwater from snow, and the water accumulates on the surface as shallow lakes, ponds, and marshes. In addition, rivers from morehumid regions flow seaward across the dry Arctic terrain. Several large rivers are in the Russian Arctic, and the Mackenzie and Yukon rivers are...
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Heat (physics)
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INTRODUCTION
Heat Loss from a House
A thermograph shows the large amount of heat lost through a house's windows during winter.
Theoretically, the molecules of a substance would exhibit no activity at the temperature termed absolute zero. See Molecule. III TEMPERATURE SCALES Five different temperature scales are in use today: the Celsius scale, known also as the Centigrade scale, the Fahrenheit scale, the Kelvin scale, the Rankine scale, andthe international thermodynamic temperature scale ( see Thermometer). The Celsius scale, with a freezing point of 0° C and a boiling point of 100° C, is widely used throughout the...
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Turbine.
steam turbine has supplanted the reciprocating engine as a prime mover in large electricity-generating plants and is also used as a means of jet propulsion. Steam turbines are used in the generation of nuclear power and in nuclear ship propulsion. They operate with fuel-fired boilers for power generation. In cogenerationapplications requiring both process heat (heat used in an industrial process) and electricity, steam is raised at high pressure in the boiler and extracted from the turbineat th...
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Population.
year AD 1, and it took more than 1,500 years to reach the 500 million mark. Growth was not steady but was marked by oscillations dictated by climate, food supply, disease, and war. Starting in the 17th century, great advances in scientific knowledge, agriculture, industry, medicine, and social organization made possible rapid acceleration inpopulation growth. Machines gradually replaced human and animal labor. People slowly acquired the knowledge and means to control disease. By 1900 the worldp...
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Europe - geography.
movement of a segment of the Earth’s crust against the stable shield during the Caledonian orogeny (about 500 to 395 million years ago) raised the mountains of Ireland,Wales, Scotland, and western Norway. Subsequent erosion has rounded and worn down these mountains in the British Isles, but the peaks of Norway still reach 2,472 m(8,110 ft). The second major geological region, a belt of sedimentary materials, sweeps in an arc from southwestern France northward and eastward through the Low Countri...
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Arctic - Geography.
The Arctic is not a frozen desert devoid of life on land or sea, even during the cold, dark winter months. Spring brings a phenomenal resurgence of plant and animal life.Low temperatures are not always the critical element—moisture, the type of soil, and available solar energy are also extremely important. Some animals adapt well toArctic conditions; for instance, a number of species of mammals and birds carry additional insulation, such as fat, in cold months. Arctic summers with extended dayli...
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Bulgaria - country.
E Climate Most of Bulgaria has a continental climate, with cold winters and hot summers. The climate in general is more severe than in other European areas of the samelatitudes, and the average annual temperature range is greater than that of neighboring countries. Severe droughts, frosts, winds, and hail storms frequently damagecrops. A Mediterranean climate, with dry summers and mild, humid winters, prevails in the valley of the southwestern Rhodope Mountains; the northern limit of theclimati...
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Mammal - biology.
On land, mammals live in many different habitats, and at a wide range of altitudes. Many mammals dig burrows as refuges or as places to raise their young, but somehave developed a largely subterranean lifestyle, feeding on small animals or plant roots beneath the soil's surface. These animals, including moles and mole-rats, digthrough the ground either with spadelike front paws or with their teeth, and they detect danger by being highly sensitive to vibrations transmitted through the soil.Most m...
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Quantum Theory
I
INTRODUCTION
Quantum Theory, in physics, description of the particles that make up matter and how they interact with each other and with energy.
electron in the same way a particle with momentum would: It bumps the electron and changes the electron’s path. The light is also affected by the collision as though itwere a particle, in that its energy and momentum changes. Momentum is a quantity that can be defined for all particles. For light particles, or photons, momentum depends on the frequency, or color, of the photon, which in turndepends on the photon’s energy. The energy of a photon is equal to a constant number, called Planck’s cons...
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Ukraine - country.
a major hazard, especially to Ukraine’s water supply. The Chernobyl’ complex was finally shut down completely in December 2000, with the financial assistance ofWestern nations. The funds were to pay for the completion of two other nuclear power plants that would produce enough power to make up for the loss of the powersupply from the Chernobyl’ plant. III PEOPLE OF UKRAINE The population of Ukraine was estimated in 2008 at 45,994,287, giving the country a population density of 76 persons per s...
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Northwest Territories - Geography.
million years ago by the severe bending (folding) and faulting (breaking) of sedimentary rock that was once part of the Interior Plains. During the Wisconsin Ice Age,alpine glaciers covered the Cordillera, and the movement of the glaciers created razor-sharp peaks and ridges in these mountains. The moving glaciers also createdbroad U-shaped valleys. To the east of the Interior Plains, the ancient rocks of the Canadian Shield are exposed at the Earth’s surface, resulting in a rough, rolling terra...
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Northwest Territories - Canadian History.
million years ago by the severe bending (folding) and faulting (breaking) of sedimentary rock that was once part of the Interior Plains. During the Wisconsin Ice Age,alpine glaciers covered the Cordillera, and the movement of the glaciers created razor-sharp peaks and ridges in these mountains. The moving glaciers also createdbroad U-shaped valleys. To the east of the Interior Plains, the ancient rocks of the Canadian Shield are exposed at the Earth’s surface, resulting in a rough, rolling terra...
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Exercise.
broad, and most studies suggest a positive relationship between physical fitness and mental achievement. The relationship between regular aerobic exercise and cardiovascular health and longevity is well established. Regular exercise leads to a reduction in the risk ofcoronary heart disease, in which fatty deposits (plaque) form in blood vessels supplying the muscular wall of the heart, compromising oxygen delivery to the heartmuscle. In addition, with regular exercise the efficiency of the heart...
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From The Adventures of Huckleberry Finn - anthology.
'Wherebouts?' says I. 'Down to Silas Phelps's place, two mile below here. He's a runaway nigger, and they've got him. Was you looking for him?' 'You bet I ain't! I run across him in the woods about an hour or two ago, and he said if I hollered he'd cut my livers out—and told me to lay down and stay where Iwas; and I done it. Been there ever since; afeard to come out.' 'Well,' he says, 'you needn't be afeard no more, becuz they've got him. He run off f'm down South, som'ers.' 'It'...
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Senegal - country.
Although most of the population works in agriculture, Senegal has a growing industrial sector, one of the largest in West Africa. Nevertheless, two cash crops remain atthe foundation of the economy—peanuts and cotton. Important technical and economic assistance has been provided by France and other countries of the EuropeanUnion and the International Bank for Reconstruction and Development (World Bank). In 2006 the gross domestic product (GDP) was $9.2 billion, or $760.90 a person. A Agriculture...
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Wireless Communications.
were large, heavy units. After the invention of the transistor in 1948, radios shrank in size to small handheld radio transceivers. Public two-way radios with severalfrequency options are widely available as well. Usually limited in range to a few miles, these units are great aids for such mobile professionals as construction workers,film crews, event planners, and security personnel. Simpler two-way radios, called walkie-talkies, have been popular children’s toys for years. Most walkie-talkiesb...
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Gambling.
C Lotteries Lotteries are another form of gambling. In a lottery, tickets are sold for a set amount and a share of the proceeds is returned to the winners, usually through a randomdraw. Most games allow players to pick their own numbers or let a computer randomly pick for them. Lotteries offer a wide variety of games, including weekly drawings,instant “scratch” tickets, daily games, and superlottos with prizes increasing until there is a winner. Large lottery prizes sometimes exceed $100 millio...
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Computer Memory.
been created, information can be retrieved but not changed. Newer technologies allow ROMs to be semi-permanent—that is, the information can be changed, but ittakes several seconds to make the change. For example, a FLASH memory acts like a ROM because values remain stored in memory, but the values can be changed. C External Memory External memory can generally be classified as either magnetic or optical, or a combination called magneto-optical. A magnetic storage device, such as a computer'shar...
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Blood.
substances. For example, a person who is blood type A positive will not make antibodies against the A or Rh markers, but will make antibodies against the B marker,which is not on that person’s own red blood cells. If blood containing the B marker (from types B positive, B negative, AB positive, or AB negative) is transfused into thisperson, then the transfused red blood cells will be rapidly destroyed by the patient’s anti-B antibodies. In this case, the transfusion will do the patient no good a...