单选题They didn"t realize how serious the problem was.

单选题The house was seriously destroyed.A. slightlyB. heavilyC. obviouslyD. sadly

单选题Every week the magazine presents the {{U}}profile{{/U}} of a well-known sports personality. A. description B. success C. evidence D. plan

单选题Initially the writer did not want to buy a hearing aid because

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个最佳答案。{{B}}第一篇{{/B}} {{B}}Ford Abandons Electric Vehicles{{/B}} The Ford motor company's abandonment of electric cars effectively signals the end of the road for the technology, analysts say. General Motors and Honda ceased production of battery-powered cars in 1999, to focus on fuel cell and hybrid electric gasoline engines, which are more attractive to the consumer. Ford has now announced it will do the same. Three years ago, the company introduced the Think City two-seater car and a golf cart called the THINK, or Think Neighbor It hoped to sell 5,000 cars each year and 10,000 carts. But a lack of demand means only about 1,000 of the cars have been produced, and less than 1,700 carts have been sold so far in 2002. "The bottom line is we don't believe that this is the future of environment transport for the mass market," Tim Holmes of Ford Europe said on Friday. "We feel we have given electric our best shot." The Think City has a range of only about 55 miles and up to a six-hour battery recharge time. General Motors' EVI electric vehicle also had a limited range, of about 100 miles. The very expensive batteries also mean electric cars cost much more than petrol-powered alternatives. An electric Toyota RAV4 EV vehicle costs over $42,000 in the US, compared with just $17,000 for the petrol version. Toyota and Nissan are, now the only major auto manufacturers to produce electric vehicles. "There is a feeling that battery electric has been given its chance. Ford now has to move on with its hybrid program, and that is what we will be judging them on," Roger Higman, a senior transport campaigner at UK Friends of the Earth, told the Environment News Service. Hybrid cars introduced by Toyota and Honda in the past few years have sold well. Hybrid engines offer greater mileage than petrol-only engines, and the batteries recharge themselves. Ford says it thinks such vehicles will help it meet planned new guidelines on vehicle emissions in the US. However, it is not yet clear exactly what those guidelines will permit. In June, General Motors and Daimler Chrysler won a court injunction, delaying by two years Californian legislation requiring car-makers to offer 100,000 zero-emission and other low-emission vehicles in the state by 2003. Car manufacturers hope the legislation will be rewritten to allow for more low-emission, rather than zero-emission, vehicles.

单选题In 1861 it seemed Uinevitable/U that the southern states would break away from the Union.

单选题Today in the United States, adult education facilities face rising demand created by {{U}}expanding{{/U}} leisure time.

单选题Peel Watch Swimmers can drown in busy swimming pools when lifeguards fail to notice that they are in trouble. The Royal Society for the Prevention of Accidents says that on average 15 people drown in British pools each year, but many more suffer major injury after getting into difficulties. Now a French company has developed an artificial intelligence system called Poseidon that sounds the alarm when it sees someone in danger of drowning. When a swimmer sinks towards the bottom of the pool, the new system sends an alarm signal to a poolside monitoring station and a lifeguard's pager. "In trials at a pool in Ancenis, near Nantes, it saved a life within just a few months," says Alistair McQuade, a spokesman for its maker, Poseidon Technologies. Poseidon keeps watch through a network of underwater and overheard video cameras. AI software analyses the images to work out swimmers trajectories (轨道，轨线). To do this reliably, it has to tell the difference between a swimmer and the shadow of someone being cast onto the bottom or side of the pool. "The underwater environment is a very dynamic one, with many shadows and reflections dancing around," says McQuade. The software does this by "projecting" a shape in its field of view onto an image of the far wall of the pool. It does the same with an image from another camera viewing the shape from a different angle. If the two projections are in the same position, the shape is identified as a shadow and is ignored. But if they are different, the shape is a swimmer and so the system follows its trajectory. To pick out potential drowning victims, anyone in the water who starts to descend slowly is added to the software's "pre-alert" list, says McQuade. Swimmers who then stay immobile on the pool bottom for 5 seconds or more are considered in danger of drowning. Poseidon double-checks that the image really is of a swimmer, not a shadow, by seeing whether it obscures the pool's floor texture when viewed from overhead. If so, it alerts the lifeguard, showing the swimmer's location on a poolside screen. The first full-scale Poseidon system will be officially opened next week at a pool in High Wycombe, Buckinghamshire. One man who is impressed with the idea is Travor Baylis, inventor of the clockwork radio. Baylis runs a company that installs swimming pools—and he was once an underwater escapologist (表演脱身术的人) with a circus. "I say full marks to them if this works and can save lives," he says. But he adds that any local authority spending 230,000—plus on a Poseidon system ought to be investing similar amounts in teaching children to swim.

阅读短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案，并填入题前的括号内。 {{B}}Where Did All the Ships Go?{{/B}} The Bermuda Triangle is one{{U}} (1) {{/U}}the greatest mysteries of the sea. In this triangular area between Florida, Puerto Rico and Bermuda in Atlantic, ships and airplanes{{U}} (2) {{/U}}to disappear more often than in{{U}} (3) {{/U}}parts of the ocean. And they do so{{U}} (4) {{/U}}leaving any sign of all accident or any dead bodies. It is{{U}} (5) {{/U}}that Christopher Columbus was the first person to record strange happenings in the area. His compass stopped working, a flame came down from the sky, and a wave 100 to 200 feet high carried his ship about a mile away. The most famous disappearance in the Bermuda Triangle was the US Naval Air Flight 19.{{U}} (6) {{/U}}December 5, 1945, five bomber planes carrying 14 men.{{U}} (7) {{/U}}on a training mission from the Florida coast. Later that day, all communications with Flight 19 were lost. They just disappeared without a trace. The next morning, 242 planes and 19 ships took part in the largest air-sea search in history. But they found nothing. Some people blame the disappearances{{U}} (8) {{/U}}supernatural forces. It is suggested the{{U}} (9) {{/U}}ships and planes were either transported to other times and places, kidnapped by aliens{{U}} (10) {{/U}}attacked by sea creatures. There are{{U}} (11) {{/U}}natural explanations, though. The US Navy says that the Bermuda triangle is one of two places on earth{{U}} (12) {{/U}}a magnetic compass points towards tree north{{U}} (13) {{/U}}magnetic north.{{U}} (14) {{/U}}planes and ships can lose their way if they don't make adjustments. The area also has changing weather and is know{{U}} (15) {{/U}}its high waves. Storms can turn up suddenly and destroy a plane or ship. Fast currents could then sweep away any trace of an accident. Bermuda Triangle 百慕大三角区 Pueto Rico 波多利加 compassn. 罗盘，指南针 supernatural adj.超自然的 kidnap v.绑架 alien n.外星人 magnetic adj. 有磁性的 1. A. from B. of C. about D. on 2. A. often B. look C. sometimes D. seem 3. A. rest B. another C. other D. others 4. A. without B. by C. from D. upon 5. A. saying B. being said C. said D. says 6. A. On B. In C. From D. Since 7. A. took up B. took as C. took after D. took off 8. A. for B. about C. on D. from 9. A. missing B. missed C. miss D. having missed 10. A. and B. or C. nor D. neither 11. A. also B. no C. more D. beside 12. A. which B. there C. where D. that 13. A. instead of B. except C. than D. nor 14. A. Similarly B. Furthermore C. However D. Therefore 15. A. as B. for C. by D. from

阅读下面这篇短文，短文后有2项测试任务：(1)1～4题要求从所给的6个选项中为第 1～4段每段选择1个正确的小标题；(2)第5～8题要求从所给的6个选项中选择4个正确的选项，分别完成每个句子。请将答案写在相应的横线上。 {{B}}Electromagnetic Energy{{/B}} White light seems to be a combination of all colors. The energy that comes from a source of light is not limited to the kind of energy you can see. Heat is given off by a flame or an electric light. On a cloudy day it is possible to get a sunburn even though you feel cool. Visible light and the kind of energy that produce warmth and sunburn are examples of electromagnetic energy. The sun is 93 million miles from the earth. Yet we can use energy from the sun because electromagnetic energy travels through space. Many other kinds of energy are also types of electromagnetic energy. Radio, television, and radarsignals travel from transmitters to receivers as low-energy electromagnetic waves. Infrared (红外线的) radiation is an electromagnetic wave. When it is absorbed by matter, heat is produced. Waves of infrared and visible light have more energy than waves of radio, television, or radar. Ultraviolet rays (紫外线) and X-rays are electromagnetic waves with even greater amounts of energy. Infrared radiation is used in cooking food and heating buildings. Sunlight and electric lights are part of our requirements for normal living. Ultraviolet radiation is useful in killing certain disease organisms. X-rays and gamma rays have so mush energy that they travel right through solid objects. They can be used to detect and treat cancer. X-rays are used in industry to find hidden cracks in metal, and in medicine to reveal broken bones. Usually we use electricity to generate electromagnetic energy. The source of most of our energy is the sun. Heat from the sun causes water to evaporate. When the water falls to the earth as rain, some of it is trapped behind dams and then used to operate electric generators. Other generators are powered by coal, but the energy stored in coal came from the sun, too. Until recently, the source of the tremendous amount of energy given off by the sun was a puzzle. If the sun depended on chemical reactions, it would have used up all its energy long ago. Experiments with electromagnetic radiation led to the theory that mass can be converted into energy. About forty years after the theory was proposed, nuclear energy was harnessed (利用) by man. Chemical energy comes from electron (电子) rearrangement. Nuclear energy comes from a Change in the nucleus of an atom. Compared with chemical reactions, nuclear reactions release millions of times more energy per pound of fuel. We now believe that the sun's energy comes from the nuclear reactions in which hydrogen is changed into helium (氦). Nuclear energy is beginning to compete with coal as an economical source of power to generate electricity. It is also being used to operate engines in large ships. Scientists continue to seek new and better methods of obtaining and using energy.

阅读下面的短文，文中有15处空白，每处空白给出了4个选项。 {{B}}Car Thieves Could Be Stopped Remotely{{/B}} Speeding off in a stolen car, the thief thinks he has got a great catch. But he is in a nasty surprise. The car is fitted with a remote immobilizer (使车辆不能调动的装置), and a radio signal from a control center miles away will ensure that once the.thief switches the engine{{U}} (1) {{/U}}, he will not be able to start it again. For now, such devices{{U}} (2) {{/U}}only available for fleets of trucks and specialist vehicles used on construction sites. But remote immobilization technology could soon start to trickle down to ordinary cars, and{{U}} (3) {{/U}}be available to ordinary cars in the UK{{U}} (4) {{/U}}two months. The idea goes like this. A control box fitted to the car incorporates{{U}} (5) {{/U}}miniature cellphone, a microprocessor and memory, and a GPS satellite positioning receiver.{{U}} (6) {{/U}}the car is stolen, a coded cellphone signal will tell the unit to block the vehicle's engine management system and prevent the engine{{U}} (7) {{/U}}restarted. There are even plans for immobilizers{{U}} (8) {{/U}}shut down vehicles on the move, though there are fears over the safety implications of such a system. In the UK, an array of technical fixes is already making{{U}} (9) {{/U}}harder for car thieves. "The pattern of vehicles crime has changed," says Martyn Randall of Thatcham, a security research organization based in Berkshire that is funded in part{{U}} (10) {{/U}}the motor insurance industry. He says it would only take him a few minutes to{{U}} (11) {{/U}}a novice how to steal a car, using a bare minimum of tools. But only ifthe caris more than 10 years old. Modem cars are a far tougher proposition, as their engine management computer will not{{U}} (12) {{/U}}tthem to start unless they receive a unique ID code beamed out by the ignition key. In the UK, technologies like this{{U}} (13) {{/U}}achieve a 31 per cent drop in vehicle-related crime since 1997. But determined criminals ore still managing to find other ways to steal cars. Often by getting hold of the owner's keys in a burglary. In 2000, 12 per cent of vehicles stolen in the UK were taken using the owner's keys double the previous year's figure. Remote-controlled immobilization system would{{U}} (14) {{/U}}a major new obstacle in the criminal's way by making such thefts pointless. A group that includes Thatcham, the police, insurance companies and security technology finns have developed standards for a system that could go on the market sooner than the{{U}} (15) {{/U}}expects. immobilizer n. 使车辆不能调动的装置 trickle v.慢慢移动 cellphonen.移动电话，手机 immobilization n.使车辆不能调动 ignition n.点火 burglaryn.夜窍行为；盗窃 1. A. off B. on C. at D. of 2. A. is B. was C. were D. are 3. A. can B. have to C. need to D. should 4. A. after B. for C. in D. at 5. A. the B. / C. a D. an 6. A. With B. If C. But D. And 7. A. helping B. being C. get. D. be 8. A. whose B. who C. that D. when 9. A. life B. Cars C. warning D. problem 10. A. about B. to C. by D. on 11. A. use B. inform C. ask D. teach 12. A. let B. allow C. make D. give 13. A. have helped' B. helped C. had helped D. was helped 14. A. speak B. have C. link D. put 15. A. lawyer B. doctor C. customer D. specialist

Paragraph 6 ______.

阅读下面的短文，文章中有5处空白，文章后有6组文字，请根据文章的内容选择5组文字，将其分别放回文章原有位置，以恢复文章原貌。请将答案填在相应的横线上。 {{B}}Why do People Shrink?{{/B}} Did you ever see the movie Honey, I shrunk the kids? It's about a wacky dad (who's also a scientist) who accidentally shrinks his kids with his homemade miniaturizing invention. Oops!{{U}} (1) {{/U}} For older people, shrinking isn't that dramatic or sudden at all. It takes place over years and may add up to only one inch or so off of their adult height (maybe a little more, maybe less), and this kind of shrinking can't be magically reversed, although there are things that can be done to stop it or slow it down.{{U}} (2) {{/U}} There are a few reasons. As people get older, they generally lose some muscle and fat from their bodies as part of the natural aging process. Gravity (the force that keeps your feet on the ground) take hold, and the bones in the spine, called vertebrae, may break down or degenerate, and start to collapse into one another.{{U}} (3) {{/U}}But perhaps the most common reason why some older people shrink is because of osteoporosis. Osteoporosis occurs when too much spongy bone tissue (which is found inside of most bones) is broken down and not enough new bone material is made.{{U}} (4) {{/U}}Bones become smaller and weaker and can easily break if someone with osteoporosis is injured. Older people—especially women, who generally have smaller and lighter bones to begin with—are more likely to develop osteoporosis. As years go by, a person with osteoporosis shrinks a little bit. Did you know that every day you do a shrinking act? You aren't as tall at the end of the day as you are at the beginning. That's because as the day goes on, water in the disks of the spine gets compressed (squeezed) due to gravity, making you just a tiny bit shorter. Don't worry, though.{{U}} (5) {{/U}} A. They end up pressing closer together, which makes a person lose a little height and become shorter. B. Once you get a good night's rest, your body recovers, and the next morning, you're standing tall again. C. Over time, bone is said to be lost because it's not being replaced. D. Luckily, there are things that people can do to prevent shrinking. E. The kids spend the rest of the movie as tiny people who are barely visible while trying to getback to their normal size. E But why does shrinking happen at all?

阅读下面的短文，文中有15处空白，每处空白给出了4个选项。 {{B}}The Animals in Desert{{/B}} Some desert animals can survive the very strong summer heat and dryness because they have very unusual characteristics. The camel, for example, can{{U}} (1) {{/U}}an increase in the temperature of its body and its blood of 9~℃. In addition, it can drink an enormous{{U}} (2) {{/U}}water at one time, then store sufficient water in its red blood cells and other parts of its body to supply its needs for two weeks or more. The kangaroo rat, on the other hand,{{U}} (3) {{/U}}all the water it needs from water that it produces during respiration. However, most animals need to{{U}} (4) {{/U}}a fairly constant body temperature, and will die if it rises more than 5 ℃.{{U}} (5) {{/U}}, they need to find some way to avoid the strong sunrays. Nor can many animals either store or produce water in their bodies, as the camel and kangaroo rat{{U}} (6) {{/U}}. So they must find ways to{{U}} (7) {{/U}}water loss from their bodies to the lowest degree. Because very few desert animals can survive the strong rays, the temperature, and the evaporation rate{{U}} (8) {{/U}}a typical summer's day, most of them are active during the night. Only{{U}} (9) {{/U}}the sun has set does the desert come fully to life. The night is relatively cool, and the darkness provides{{U}} (10) {{/U}}, not only from the sun, but also from other animals and from the birds. So the coming of darkness is the signal{{U}} (11) {{/U}}the large majority of animals and insects to continue their search for water and food. When morning comes, most of them seek{{U}} (12) {{/U}}again. Many go underground; nearly all find somewhere shady where they can avoid the sunrays. For many kinds of insects, living in the desert is{{U}} (13) {{/U}}than for animals. Like many desert plants, they have a waterproof skin which{{U}} (14) {{/U}}water loss by evaporation. In addition, some insects spend all or most of their life below ground. Here, for most of the year at least, there is{{U}} (15) {{/U}}wetness, and it is generally cooler than on the surface. 1. A. carry B. bear C. effect D. delay 2. A. amount B. number C. level D. sum 3. A. obtains B. consumes C. brings D. replaces 4. A. raise B. reject C. maintain D. regulate 5. A. However B. Again C. Instead D. Therefore 6. A. can B. may C. must D. need 7. A. quicken B. reduce C. lighten D. keep 8. A. in B. to C. of D. through 9. A. after B. since C. until D. before 10. A. prevention B. protection C. possession D. permission 11. A. for B. with C. from D. among 12. A. food B. shelter C. water D. work 13. A. easier B. better C. safer D. harder 14. A. causes B. changes C. prevents D. suffers 15. A. little B. plentiful C. thorough D. some

阅读下面这篇短文，短文后有2项测试任务：(1)1～4题要求从所给的6个选项中为相应的段落选择1个正确的小标题；(2)第5～8题要求从所给的6个选项中选择4个正确的选项，分别完成每个句子。请将答案写在相应的横线上。 {{B}}Volts from the Sky{{/B}} Lightning has caused awe and wonder since old times. Although Benjamin Franklin demonstrated lightning as an enormous electrical discharge more than 200 years ago, many puzzles still surround this powerful phenomenon. Lightning is generated when electrical charges separate in rain clouds, though processes'are still not fully understood. Typically, positive charges build at the cloud top, while the bottom becomes negatively charged. In most instances of cloud-to-ground lightning, the negatively charged lower portion of the cloud repels negatively charged particles on the ground's surfaces, making it become positively charged. The positive charge on the ground gathers at elevated points. A flow of electrons begins between the cloud and earth. When the voltage charge becomes large enough, it breaks through the insulating barrier of air, and electrons zigzag earthward. We see the discharge as lightning. Lightning can occur within a cloud, between clouds, or between clouds and the ground. The first variety, intra-cloud lightning, is the most frequent but is often hidden from our view. Cloud-to-ground lightning, making up about 20 percent of lightning discharges, is what we usually see. Lightning comes in several forms, including sheet, ribbon, and ball. Intra-cloud lightning can illuminate a cloud so it looks like a white sheet, hence its name. When cloud-to-ground lightning occurs during strong winds, they can shift the lightning channel sideways, so it looks like a ribbon. The average lightning strike is more than 3 miles long and can travel at a tenth of the speed of light. Ball lightning, the rarest and most mysterious form, derives its name from the small luminous ballthat appears near the impact point, moves horizontally, and lasts for several seconds. Thunder is generated by the tremendous heat released in a lightning discharge. Temperatures near the discharge can reach as high as 50,000F within thousandths of a second. This sudden heating acts as an explosion, generating shock waves we hear as thunder. About 2,000 thunderstorms are occurring in the world at any time, generating about 100 lightning strikes every second, or 8 million daily. Within the United States, lightning strikes are estimated at 20 million a year, or about 22,000 per day. You have a 1-in-600,000 chance of being struck by lightning during your lifetime. Lightning can strike twice or more in the same spot. The Empire State Building in New York is struck by lightning about two dozen times annually. You can measure how far you are from a lightning strike by counting the seconds between viewing the flash and hearing the bang, and then dividing by five. This approximates the mileage.

阅读下面的短文，文中有15处空白，每处空白给出了4个选项。 {{B}}Save Energy at Home{{/B}} On the average, Americans waste as much energy as two-thirds of the world's population consumes. That's{{U}} (1) {{/U}}the result of driving inefficient cars, using inefficient appliances, and living and working in poorly insulated buildings. Then what can you do to improve the{{U}} (2) {{/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}} (3) {{/U}}over their lifetimes. The most energy-efficient models{{U}} (4) {{/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}} (5) {{/U}}bills with products that carry the Energy Star. Switch to compact fluorescent bulbs. — Change the three bulbs you use{{U}} (6) {{/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}} (7) {{/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}} (8) {{/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}} (9) {{/U}}temperature before you wake up. Turn off the lights. —{{U}} (10) {{/U}}lights and other electrical appliances such as televisions and radios when you're not using them. lnstall automatic timers for lights that people in your house frequently forget to turn them off when{{U}} (11) {{/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}} (12) {{/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}} (13) {{/U}}days, open blinds to let the sun light your home for free. Also remember that{{U}} (14) {{/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}} (15) {{/U}} dioxide n.二氧化物 insulate adj. 隔热 thermostat n. 温度自动调节器 rating n.等级级别 timer n. 定时器 fluorescent adj.荧光的 blind n.百叶窗 1. A. unlikely B. largely C. tremendously D. vastly 2. A. tool B. factor C. fact D. situation 3. A. prize B. label C. cost D. position 4. A. carry B. bring C. change D. return 5. A. phone B. water C. food D. energy 6. A. less B. most C. rarely D. seldom 7. A. Moreover B. However C. Therefore D. So 8. A. corrected B. changed C. set D. repaired 9. A. comfortable B. common C. convenient D. dramatic 10. A. Tum over B. Turn on C. Turn off D. Turn out 11. A. decorating B. using C. repairing D. leaving 12. A. station B. resources C. supply D. shortage 13. A. bright B. cloudy C. hot D. dark 14. A. air B. rain C. wind D. sunlight 15. A. layers B. levels C. degrees D. points

Where Have All the Bees Gone? Scientists who study insects have a real mystery on their hands. All across the country, honeybees are leaving their hives and never returning. Researchers call this phenomenon colony-collapse disorder. According to surveys of beekeepers across the country, 25 to 40 percent of the honeybees in the United States have vanished from their hives since last fall. So far, no one can explain why. Colony collapse is a serious concern because bees play an important role in the production of about one-third of the foods we eat. As they feed, honeybees spread pollen from flower to flower. Without this process, a plant can't produce seeds or fruits. Now, a group of scientists and beekeepers have teamed up to try to figure out what's causing the alarming collapse of so many colonies. By sharing their expertise in honeybee behavior, health, and nutrition, team members hope to find out what's contributing to the decline and to prevent bee disappearances in the future. It could be that disease is causing the disappearance of the bees. To explore that possibility, Jay Evans, a researcher at the United States Department of Agriculture (USDA Bee Research Laboratory, examines bees taken from colonies that are collapsing. "We know what s healthy bee should look like on the inside, and we can look for physical signs of disease," he says. And bees from collapsing colonies don't look very healthy. "Their stomachs are worn down, compared to the stomachs of healthy bees," Evans says. It may be that a parasite is damaging the bees' digestive organs. Their immune systems may not be working as they should. Moreover, they have high levels of bacteria inside their bodies. Another cause of colony-collapse disorder may be certain chemicals that farmers apply to kill unwanted insects on crops, says Jerry Hayes, chief bee inspector for the Florida Department of Agriculture. Some studies, he says, suggest that a certain type of insecticide affects the honeybee's nervous system (which includes the brain) and memory. "It seems like honeybees are going out and getting confused about where to go and what to do," he says. If it turns out that a disease is contributing to colony collapse, bees' genes could explain why some colonies have collapsed and others have not. In any group of bees there are many different kinds of genes. The more different genes a group has, the higher the group's genetic diversity. So far scientists haven't determined the role of genetic diversity in colony collapse, but it's a promising theory, says Evans.

The International Science Olympiads are held once every two years．

阅读下面这篇短文，短文后有2项测试任务：(1)1～4题要求从所给的6个选项中为相应段落每段选择1个正确的小标题：(2)第5～8题要求从所给的6个选项中选择4个正确的选项，分别完成每个句子。请将答案填在相应的横线上。 {{B}}More Than 8 Hours Sleep Too Much of a Good Thing{{/B}} Although the dangers of too little sleep are widely known, new research suggests that people who sleep too much may also suffer the consequences. Investigators at the University of California in San Diego found that people who clock up 9 or 10 hours each weeknight appear to have more trouble falling and staying asleep, as well as a number of other sleep problems, than people who sleep 8 hours a night. People who slept only 7 hours each night also said they had more trouble falling asleep and feelipg refreshed after a night's sleep than 8-hour sleepers. These findings, which DL Daniel Kripke reported in the joumal Psychosomatic Medicine, demonstrate that people who want to get a good night's rest may not need to set aside. more than 8 hours a night. He added that "it might be a good idea" for people who sleep more than 8 hours each night to consider reducing the mount of time they spend in bed, but cautioned that more research is needed to confirm this. Previous studies have shown the potential dangers of chronic shortages of sleep — for instance, one report demonstrated that people who habitually sleep less than 7 hours each night have a higher risk of dying within a fixed period than people who sleep more. For the current report, Kripke reviewed the responses of 1,004 adults to sleep questionnaires, in which participants indicated how much they slept during the Week and whether they experienced any sleep problems. Sleep problems included waking in the middle of the night, arising early in the morning and being unable to fall back to sleep, and having fatigue interfere with day-to-day functioning. KriDke found that people who slept between 9 and 10 hours each night were more likely to report experiencing each sleep problem than people who slept 8 hours. In an interview, Kripke noted that long sleepers may struggle to get rest at night simply because they spend too much time in bed. As evidence, he added that one way to help insomnia is to spend less time in bed. "It stands to reason that if a person spends too long a time in bed, then they'll spend a higher percentage of time awake." he said.