单选题The leaves have been swept into huge {{U}}heaps{{/U}}. A.loads B.layers C.pyramids D.piles

单选题We lived for years in a {{U}}perpetual{{/U}} state of fear

单选题Changes in Museums Museums have changed. They are no longer places that one "should" visit, they are places to enjoy and learn. At a science museum in Ontario, Canada, you can feel your hair stand on end as harmless electricity passes through your body. At the Metropolitan (成都市的) Museum of Art in New York City, you can look at the seventeenth century instruments while listening to their music. At New York's American Museum of Natural History recently, you can help make a bone-by-bone reproduction of the museum's dinosaur(恐龙), a beast that lived 200 million years age. More and more museum directors are realizing that people learn best when they can somehow become part of what they are seeing. In many science museums, for example, there are no guided tours. The visitor is encouraged to touch, listen, operate, and experiment so as to discover scientific principles for himself. The purpose is not only to provide fun but also to help people feel at home in the world of science. The theory is that people who do not understand science will probably fear it, and those who fear science will not use it to best advantage. One cause of all these changes is the increase in wealth and leisure time. Another cause is the rising percentage of young people in the population. Many of these young people are college students or college graduates, Leon F. Twiggs, a young black professor of art once said, "They see things in a new and different way. They are not satisfied to stand and look at works of art; they want art they can participate(参加) in. "The same is true of science and history.

单选题It seems highly unlikely that she will pass the exam.

单选题The industrial revolution modified the whole structure of English society.

单选题下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文并根据短文回答其后面的问题，从4个选项中选择1个最佳答。{{B}}第一篇{{/B}} {{B}}Food and Health{{/B}} The food you eat does more than provide energy. It can have a dramatic effect on your body’s ability to fight off heart disease, cancer, diabetes, high blood pressure, stroke, and weak bones. With remarkable consistency, recent research has found that a diet high in plant-based foods—fruits, vegetables, dried peas and beans, grains, and starchy staples such as potatoes—is the body’s best weapon in {{U}}thwarting{{/U}} many health-related problems. These foods work against so many diseases that the same healthy ingredients you might use to protect your heart or ward off cancer will also benefit your intestinal tract and bones. Scientists have recently estimated that approximately 30 to 40 percent of all cancers could be avoided if people ate more fruits, vegetables, and plant-based foods and minimized high-fat, high-calorie edibles that have scant nutritional value. Up to 70 percent of cancers might be eliminated if people also stopped smoking, exercised regularly, and controlled their weight. In the past, researchers had linked fat consumption with the development of cancers, but they currently believe that eating fruits, vegetables, and grains may be more important in preventing the disease than not eating fat. “The evidence about a high-fat diet and cancer seemed a lot stronger several years ago than it does now,” says Melanie Polk, a registered dietitian and director of nutrition education at the American Institute for Cancer Research. The road to strong bones is paved with calcium-rich food. Leafy green vegetables and low-fat dairy products are excellent sources of calcium, the mineral that puts stiffness into your skeletal system and keeps your bones from turning rubbery and fragile. Your body uses calcium for more than keeping your bones strong. Calcium permits cells to divide, regulates muscle contraction and relaxation, and plays an important role in the movement of protein and nutrients inside cells. If you don’t absorb enough from what you eat to satisfy these requirements, your body will take it from your bones. Because your body doesn’t produce this essential mineral, you must continually replenish the supply. Even though the recommended daily amount is 1,200 mg, most adults don’t eat more than 500 mg. One reason may have been the perception that calcium-rich dairy products were also loaded with calories. “In the past, women, in particular, worried that dairy products were high in calories,” says Letha Y. Griffin, M. D., of Peachtree Orthopaedics in Atlanta. “But today you can get calcium without eating any high-fat or high-calorie foods by choosing skim milk or low-fat yogurt.” Also, low fat dairy products contain phosphorous and magnesium and are generally fortified with vitamin D, all of which help your body absorb and use calcium. If you find it difficult to include enough calcium in your diet, ask your doctor about supplements. They’re a potent way to get calcium as well as vitamin D and other minerals. But if you rely on pills instead of a calcium-rich diet, you won’t benefit from the other nutrients that food provides. Getting the recommended vitamin D may be easy, since your body makes the vitamin when your skin is exposed to the sun’s rays.

单选题People's attitudes to the TV program have changed a lot.A. displayedB. shownC. shiftedD. described

单选题I have extreme sense of happiness at this moment.A. hopeB. wishC. feelingD. dream

单选题She has proved that she can be {{U}}relied on{{/U}} in a crisis.

单选题Most babies can Utake in/U a wide range of food easily.

单选题The Spanish, French, Dutch, and English all {{U}}vied for{{/U}} North American territory.

单选题Nitrogen is the most plentiful gas in the atmosphere .

单选题Certain colors when incorporated into the decor of a room can produce a cozy atmosphere. A. light B. roomy C. cluttered D. comfortable

单选题Jane said that she couldn"t tolerate the long hours.

单选题Sharks Perform a Service for Earth's Waters It is hard to get people to think of sharks as anything but a deadly enemy. They are thought to (51) people frequently. But these fish perform a (52) service for earth's waters and for human beings. Yet business and sport fishing are threatening their (53) . Some sharks are at risk of disappearing from (54) . Warm weather may influence both fish and shark activity. Many fish swim near coastal areas (55) their warm waters. Experts say sharks may follow the fish into the same areas, (56) people also swim. In fact, most sharks do not purposely charge at or bite humans. They are thought to mistake a person (57) a sea animal, such as a seal or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up. Those are the (58) when sharks are looking for food. Experts also say that bright colors and shiny jewelry may cause sharks to attack. A shark has an extremely good sense of smell. It can find small amounts of substances in water, such as blood, body liquids and (59) produced by animals. These powerful (60) help sharks fred their food. Sharks eat fish, any (61) sharks, and plants that live in the ocean. Medical researchers want to learn more about the shark's body defense, and immune (62) against disease. Researchers know that sharks (63) quickly from injuries. They study the shark in hopes of finding a way to fight human disease. Sharks are important for the world's (64) . They eat injured and diseased fish. Their hunting activities mean that the numbers of other fish in ocean waters do not become too (65) . This protects the plants and other forms of life that exist in the oceans.

单选题 Save Energy at Home On the average, Americans waste as much energy as two-thirds of the world's population consumes. That's {{U}} {{U}} 1 {{/U}} {{/U}}the result of driving inefficient cars, using inefficient appliances, living and working in poorly insulated buildings. Then what can you do to improve the {{U}} {{U}} 2 {{/U}} {{/U}}? Buy energy-efficient products—Buy new appliances or electronics of the highest energy-efficiency rating. New energy efficient models may cost more initially, but have a lower operating {{U}} {{U}} 3 {{/U}} {{/U}}over their lifetimes. The most energy-efficient models {{U}} {{U}} 4 {{/U}} {{/U}}the Energy Star label which identifies products that use 20—40 percent less energy than standard new products. According to the EPA, the typical American household can save about $400 per year in {{U}} {{U}} 5 {{/U}} {{/U}}bills with products that carry the Energy Star. Switch to compact fluorescent bulbs (荧光灯)—Change the three bulbs you use {{U}} {{U}} 6 {{/U}} {{/U}}in your house to compact fluorescents. Each compact fluorescent bulb will keep half a ton of carbon dioxide out of the air over its lifetime. {{U}} {{U}} 7 {{/U}} {{/U}}, compact fluorescent bulbs last ten times as long and can save $30 per year in electricity costs. Set heating and cooling temperatures correctly—Check thermostats in your home to make sure they are {{U}} {{U}} 8 {{/U}} {{/U}}at a level that doesn't waste energy. Get an electronic thermostat that will allow your furnace to heat the house to a lower temperature when you're sleeping and return it to a more {{U}} {{U}} 9 {{/U}} {{/U}}temperature before you wake up. Turn off the lights—{{U}} {{U}} 10 {{/U}} {{/U}}lights and other electrical appliances such as televisions and radios when you're not using them. Install automatic timers for lights in case that people in your house frequently forget to turn them off when {{U}} {{U}} 11 {{/U}} {{/U}}a room. Choose renewable energy—Many consumers can now choose their energy supplier. If you have a choice, choose an electric utility that uses renewable power {{U}} {{U}} 12 {{/U}} {{/U}}, such as solar, water or wind. Let the sun shine in—The cheapest and most energy-efficient light and heat source is often right outside your windows. On {{U}} {{U}} 13 {{/U}} {{/U}}days, open blinds to let the sun light your home for free. Also remember that {{U}} {{U}} 14 {{/U}} {{/U}}entering a room equals passive solar heating. Even on cold winter days, sun streaming into a room can raise the temperature by several {{U}} {{U}} 15 {{/U}} {{/U}}.

单选题Up to now, the work has been easy.

单选题Poor children should not be Udeprived/U of the opportunity to participate in sports whenever possible.

单选题I catch a cold now and then .

单选题By the 1930s, the wolf had vanished from the American West.