单选题He found that cool weather is much more favorable for creative thinking than is summer heat. This does not mean that all people are less intelligent in the summer than they are during the rest of the year. It does mean, however, that the mental abilities of large numbers of people tend to be lowest in the summer. Spring appears to be the best period of" the year for thinking. One reason may be that in the spring man's mental abilities are affected by the same factors that bring about great changes in all of nature. Fall is the next best season, then winter. As for summer, it seems to be a good time to take a long vacation from thinking. Most people's mental abilities seem to be highestA. in spring.B. in summer.C. in fall.D. in winter.

单选题Singing Alarms Could Save the Blind If you cannot see, you may not be able to find your way out of a burning building—and that could be fatal. A company in Leeds could change all that 1 directional sound alarms capable of guiding you to the exit. Sound Alert, a company 2 the University of Leeds, is installing the alarms in a residential home for 3 people in Sommerset and a resource centre for the blind in Cumbria. 4 produce a wide range of frequencies that enable the brain to determine where the 5 is coming from. Deborah Withington of Sound Alert says that the alarms use most of the frequencies that can be 6 by humans. "It is a burst of white noise 7 people say sounds like static on the radio," she says. "Its life-saving potential is great." She conducted an experiment in which people were filmed by thermal-imaging cameras trying to find their way out of a large 8 room. It 9 them nearly four minutes to find the door 10 a sound alarm, but only 15 seconds with one. Withington studies how the brain 11 sounds at the university. She says that the 12 of a wide band of frequencies can be pinpointed more easily than the source of a narrow band. Alarms 13 the same concept have already been installed on emergency vehicles. The alarms will also include rising or falling frequencies to indicate whether people should go up 14 down stairs. They were 15 with the aid of a large grant from British Nuclear Fuels.

单选题阅读下面这篇短文，短文后列出了7个句子，请根据短文的内容对每个句子作出判断。如果该句提供的是正确信息，清选择A项；如果该句提供的是错误信息，请选择B项；如果该句的信息文章中没有提及，请选择C项。 {{B}}Food and Cancer{{/B}} Medical Experts have suspected for many years that there is a strong link between what a person eats and cancer. They say a new study provides the first evidence that vitamins could reduce a person's chance of developing cancer. A team of Chinese and American scientists did the study. They are from American National Cancer Institute and the Cancer Institute of the Chinese Academy of Medical sciences in Beijing. The Journal of the National Cancer Institute published the results of the study. About thirty thousand people between the ages of 40 to 69 took part in the study. They were form the northern central Chinese area of Linxian. Most of them took vitamins and minerals every day for five years. Linxian was chosen because the people there have an extremely high rate of cancer of stomach and esophagus. Researchers believe that fungus and molds in local foods may be partly responsible for the high cancer rate. Researchers divided those into eight groups. Seven of the groups received different mixtures of vitamins and minerals daily. The amounts of the vitamins and minerals were 1 to 2 times greater than what American health officials say is needed. The eighth group received sugar pills that had no effect. Those who seemed to fain the most received a mixture of a form of vitamin A called B-carotene, vitamin E and the mineral selenium. The vitamin and mineral are believed to prevent damage to cells caused by cancer-causing substances. Researchers reported a 13 percent drop in cancer rates in those who took B-carotene, vitamin E and selenium. They also found a 10 percent drop in the number of deaths caused by strokes from bursting blood vessels. Scientists warn that it is too soon to know if the effect, would be the same among people in other countries. They note that the people in Linxian eat foods that lack necessary vitamins and minerals. Chinese officials will continue to record the health records of the people in Linxian for many years. For now officials reportedly are considering using the results of the study. They want to find a way to improved the health of people in Linxian and other small towns in China.

单选题 Lateral Thinking Lateral thinking (迂回思维), first described by Edward de Bono in 1967, is just a few years older than Edward's son. You might imagine that Caspar was raised to be an adventurous thinker, but de Bono name was so famous, Casper's parents worried that any time he would say something bright at school, his teachers might snap, "Where do you get that idea from?" "We had to be careful and not overdo it," Edward admits. Now Casper is at Oxford—which once looked unlikely because he is also slightly dyslexic (诵读困难). In fact, when he was applying to Oxford, none of his school teachers thought he had a chance. "So then we did several thinking sessions," his father says, "using my techniques and, when he went up for the exam, he did extremely well." Soon after, Edward de Bono decided to write his latest book, "Teach Your Children How to Think", in which he transforms the thinking skills he developed for brain—storming businessmen into informal exercises for parents and children to share. Thinking is traditionally regarded as something executed in a logical sequence, and everybody knows that children aren't very logical. So isn't it an uphill battle, trying to teach them to think? "You know," Edward de Bono says, "if you examine people's thinking, it is quite unusual to find faults of logic. But the faults of perception are huge! Often we think ineffectively because we take too limited a view." "Teach Your Child How to Think" offers lessons in perception improvement, of clearly seeing the implications of something you are saying and of exploring the alternatives.

单选题The stories of Sarah Orne Jewett are considered by many to be more {{U}}authentically{{/U}} regional than those of Bret Harte.

单选题The building ______ at this moment will be a modern hospital.A. builtB. being builtC. to be builtD. building

单选题It can be inferred from the passage that

单选题She was sent a box of chocolates along with a letter saying she was fired .

单选题Food Fright Experiments under way in several labs aim to create beneficial types of genetically modified (GM) foods, including starchier potatoes and caffeine-free coffee beans. Genetic engineers are even trying to transfer genes from a cold-water fish to make a frost-resistant tomato. A low-sugar GM strawberry now in the works might one day allow people with health problems such as diabetes to enjoy the little delicious red fruits again. GM beans and grains supercharged with protein might help people at risk of developing kwashiorkor. Kwashiorkor, a disease caused by severe lack of protein, is common in parts of the world where there are severe food shortages. Commenting on GM foods, Jonathon Jones, a British researcher, said, "The future benefits will be enormous, and the best is yet to come." To some people, GM foods are no different from unmodified foods. "A tomato is a tomato," said Brian Sansoni, an American food manufacturer. Critics of GM foods challenge Sansoni"s opinion. They worry about the harm that GM crops might do to people, other animals, and plants. In a recent lab study conducted at Cornell University, scientists tested pollen made by Bt corn, which makes up one-fourth of the U.S. corn crop. The scientist sprinkled the pollen onto milkweed, a plant that makes a milky juice and is the only known food source of the monarch butterfly caterpillar. Within four days of munching on the milkweed leaves, almost half of a test group of caterpillars had died. "Monarchs are considered to be a flagship species for conservation," said Cornel1 researcher Linda Raynor. "This is a warning bell." Some insects that are not killed by GM foods might find themselves made stronger. How so? The insecticides used to protect most of today"s crops are sprayed on the crops when needed and decay quickly in the environment. But GM plants produce a continuous level of insecticide. Insect species feeding on those crops may develop resistance to the plants and could do so in a hurry, say the critics. Insects may also develop a resistance to the insecticide Bt. At the forum on GM food held last year in Canada, GM crops that have been made resistant to the herbicide might crossbreed with wild plants, creating "superweeds" that could take over whole fields. So where do you stand? Should GM foods be banned in the United States, as they are in parts of Europe? Or do their benefits outweigh any of the risks they might carry?

单选题China does a lot of trade with many countries.

单选题"Salty" Rice Plant Boosts Harvests British scientists are breeding a new generation of rice plants that will be able to grow in soil containing salt water. Their work may enable abandoned farms to become productive once more. Tim Flowers and Tony Yeo, from Sussex University's School of Biological Sciences, have spent several years researching how crops, such as rice, could be made to grow in water that has become salty. The pair have recently begun a three-year programme, funded by the Biotechnology and Biological Sciences Research Council, to establish which genes enable some plants to survive salty conditions. The aim is to breed this capability into crops, starting with rice. It is estimated that each year more than 10m hectares (公顷) of agricultural land are lost because salt gets into the soil and stunts (妨碍生长) plants. The problem is caused by several factors. In the tropics, mangroves (绿树林) that create swamps (沼泽) and traditionally formed barriers to sea water have been cut down. In the Mediterranean, a series of droughts have caused the water table to drop, allowing sea water to seep (渗透) in. In Latin America, irrigation often causes problems when water is evaporated (蒸发) by the heat, leaving salt deposits behind. Excess salt then enters the plants and prevents them functioning normally. Heavy concentrations of minerals in the plants stop them drawing up the water they need to survive. To overcome these problems, Flowers and Yeo decided to breed rice plants that take in very little salt and store what they do absorb in cells but do not affect the plants' growth. They have started to breed these characteristics into a new rice crop, but it will take about eight harvests before the resulting seeds are ready to be considered for commercial use. Once the characteristics for surviving salty soil are known, Flowers and Yeo will try to breed the appropriate genes into all manners of crops and plants. Land that has been abandoned to nature will then be able to bloom again, providing much needed food in the poorer countries of the world.

单选题They are endeavoring to change society as a whole.A. tryingB. workingC. doingD. making

单选题She answered the difficult question, which was an immense load off her heart. A. natural B. fatal C. tiny D. enormous

单选题Transportation For many years in the desert, camels used to be the only form of transportation (运输). Before the age of modern trains, camel trains were used to carry all the goods for trading between Central Africa and Europe. Traders sometimes put together camel trains with 10,000 to 15,000 animals. Each animal often carried as much as 400 pounds and could travel twenty miles a day. This form of transportation used to be so important that camels were called "ships of the desert". Now modem trains travel across the desert in a very short time. One engine can pull as much weight as 135,000 camels. In addition, trains use special cars (车厢) for their load. Refrigerator cars carry food; boxcars (棚车) carry heavy goods; stock cars carry animals; and tank cars carry oil. Air travel is also a modem means of transportation, but it has changed since the early 20th century. The earliest planes were biplanes (双翼飞机), with two sets of wings. The top speed of this plane was 60 miles per hour. The pilots used to sit or lie on the wings in the open air. The plane engines sometimes stopped in the middle of a trip. It used to be impossible to fly in bad weather. In snow or in rain, the wings frequently became icy. Then the plane might go down. Mechanical improvements during the First World War changed airplanes. Monoplanes (单翼飞机) took the place of biplanes. Pilots flew inside of covered cabins. Still, even these planes were small and expensive. Only rich people used to be able to travel in airplanes. Now modem jets make air travel possible for all people. No place in the world is more than 24 hours away by jet. Further improvements have lowered the cost of flying, and they have made air travel much safer than it used to be. A modern 707 can carry 170 people and can fly at 600 miles per hour. People never used to eat, sleep, or watch movies on airplanes. Now these things are a normal part of air travel.

单选题The Foreign Service is a {{U}}branch{{/U}} of the Department of State．

单选题That player is etemally arguing with the refereeA. desperatelyB. constantlyC. eventuallyD. extensively

单选题Would you please Ucall/U my husband aS soon as possible?

单选题To solve the problem of dry mouths, one is advised to take cool milk.

单选题Oil and Economy Could the bad old days of economic decline be about to return? Since OPEC agreed to supply-cuts in March, the price of crude oil has jumped to almost $ 26 a barrel, up from less than $10 last December. This near-tripling of oil prices calls up scary memories of the 1973 oil shock, when prices quadrupled, and 1979—1980, when they also almost tripled. Both previous shocks resulted in double-digit inflation and global economic decline. So where are the headlines warning of gloom and doom this time? The oil price was given another push up this week when Iraq suspended oil exports. Strengthening economic growth, at the same time as winter grips the northern hemisphere, could push the price higher still in the short term. Yet there are good reasons to expect the economic consequences now to be less severe than in the 1970s. In most countries the cost of crude oil now accounts for a smaller share of the price of petrol than it did in the 1970s. In Europe, taxes account for up to four-fifths of the retail price, so even quite big changes in the price of crude have a more muted effect on pump prices than in the past. Rich economies are also less dependent on oil than they were, and so less sensitive to swings in the oil price. Energy conservation, a shift to other fuels and a decline in the importance of heavy, energy-intensive industries have reduced oil consumption. Software, consultancy and mobile telephones use far less oil than steel or car production. For each dollar of GDP (inconstant prices) rich economies now use nearly 50% less oil than in 1973. The OECD estimates in its latest Economic Outlook that, if oil prices averaged $22 a barrel for a full year, compared with $13 in 1998, this would increase the oil import bill in rich economies by only 0.25-0.5% of GDP. That is less than one-quarter of the income loss in 1974 or 1980. On the other hand, oil-importing emerging economies-to which heavy industry has shifted-have become more energy-intensive, and so could be more seriously squeezed. One more reason not to lose sleep over the rise in oil prices is that, unlike the rises in the 1970s, it has not occurred against the background of general commodity-price inflation and global excess demand. A sizable portion of the world is only just emerging from economic decline. The Economist's commodity price index is broadly unchanging from a year ago. In 1973 commodity prices jumped by 70%, and in 1979 by almost 30%.

单选题Some People Do Not Taste Salt like Others Low-salt foods may be harder for some people to like than others, according, to a study by a Penn State College of Agricultural Sciences food scientist. The research indicates that genetic factors influence some of the difference in the levels of salt we like to eat. Those conclusions are important because recent, well-publicized (大力宣传的) efforts to reduce the salt content in food have left many people struggling to accept food that simply does not taste as good to them as it does to others, pointed out John Hayes, lead investigator on the study. Diets high in salt can increase the risk of high blood pressure and stroke. That is why public health experts and food companies are working together on ways to help consumers lower salt intake through foods that are enjoyable to eat. This study increases understanding of salt preference and consumption. The research involved 87 carefully screened participants who sampled salty foods such as soup and chips, on multiple occasions, spread out over weeks. Test subjects were 45 men and 42 women, reportedly healthy, ranging in age from 20 to 40. They rated the intensity of taste on a commonly used scientific scale, ranging from barely detectable to strongest sensation of any kind. "Most of us like the taste of salt. However, some individuals eat more salt, both because they like the taste of saltiness more, and also because it is needed to block other unpleasant tastes in food, " said Hayes. "Supertasters, people who experience tastes more intensely, consume more salt than nontasters. Snack foods have saltiness as their primary flavor, and at least for these foods, more is better, so the supertasters seem to like them more. " However, supertasters also need higher levels of salt to block unpleasant bitter tastes in foods such as cheese, Hayes noted. "For example, cheese is a wonderful blend of dairy flavors from fermented (发酵地) milk, but also bitter tastes from ripening that are blocked by salt, " he said. "A supertaster finds low-salt cheese unpleasant because the bitterness is too pronounced. " Hayes cited research done more than 75 years ago by a chemist named Fox and a geneticist named Blakeslee, showing that individuals differ in their ability to taste certain chemicals. As a result, Hayes explained, we know that a wide range in taste acuity(敏锐) exists, and this variation is as normal as variations in eye and hair color.