单选题"Copy the ways of nature", we were told. Yes, copy Nature—for everything comes directly or indirectly from natural things. Often we have to put our knowledge to work, treating Nature's materials so as to make them serve our purposes better. We could, certainly, take the skin from a dead animal and at once make a pair of shoes with it; but they wouldn't be very good shoes. For our purpose it is better first to treat the skin with chemicals that turn it into leather. Why is it necessary for us to treat Nature's material?A. An animal's skin is not really useful to us.B. Our purposes can be better served.C. Natural materials are limited.D. It is difficult to copy natur

单选题From my standpoint, you know, this thing is just funny. A. position B. point of view C. knowledge D. opinion

单选题There is more rainfall

单选题A Dolphin and an Astronomer One day in 1963, a dolphin named Elvar and a famous astronomer, Carl Sagan, were playing a little game. The astronomer was visiting an institute which was looking into the way dolphins communicate with each other. Sagan was standing on the edge of one of the tanks where several of these friendly, highly intelligent creatures were kept. Elvar had just swum up alongside him and had turned on his back. The dolphin wanted Sagan to scratch his stomach again, as the astronomer had done twice before. Elvar looked up at Sagan, waiting. Then, after a minute or so, the dolphin leapt up through the water and made a sound just like the word "more". The astonished astronomer went to the director of the institute and told him about the incident. "Oh, yes. That's one of the words he knows," the director said, showing no surprise at all. Dolphins have bigger brains in proportion to their body size than humans have, and it has been known for a long time that they can make a number of sounds. What is more, these sounds seem to have different functions, such as warning each other of danger. Sound travels much faster and much further in water than it does in air. That is why the parts of the brain that deal with sound are much better developed in dolphins than in humans. But can it be said that dolphins have a "language", in the real sense of the word? Scientists don't agree on this. A language is not just a collection of sounds, or even words. A language has a structure and what we call a grammar. The structure and grammar of a language help to give it meaning. For example, the two questions "Who loves Mary?" and "Who does Mary love?" mean very different things. If you stop to think about it, you will see that this difference doesn't come from the words in the question but from the difference in structure. That is why the question "Can dolphins speak?" can't be answered until we find out if dolphins not only make sounds but also arrange them in a grammatical order which affects their meaning.

单选题I soon perceived that I could not change his mind.A. discoveredB. noticedC. sawD. sensed

单选题Please don't refuse his help because he is so kind a man.A. mm downB. go downC. put downD. pull down

单选题On the table was a vase filled with Uartificial /U flowers

单选题Our arrangements were thrown into complete turmoil .

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 (红树林) 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The conference {{U}}explored{{/U}} the possibility of closer trade links. A. denied B. investigated C. stressed D. created

单选题下面的短文后列出了7个句子，请根据短文的内容对每个句子做出判断：如果该句提的是正确信息，请选择A：如果该句提的是错误信息，请选择B：如果该句的信息文中没有提及，请选择C。 Irradiating Food Irradiating fruits, vegetables, pork and chicken to kill insects and bacteria has been approved by the Food and Drug Administration over the past decade or so. Irradiation of other meats, such as beef and lamb, is being reviewed. Federal approval does not require that industry adopt the process, and few food processors presently offer irradiated products. Market studies have shown that many consumers are afraid that eating irradiated foods may cause cancer, despite scientific studies that prove the safety of treated foods. Some people argue that more severe government inspection, higher food-safety standard and more careful-preparation practices by consumers are all that is needed to ensure that food is safe. Consequently, companies currently see no need to spend millions of dollars outfitting processing plants with the equipment necessary for a process that very few shoppers are in favor of. All supermarkets that sell irradiated food must label the food either directly on the packaging, or, in the case of bulk items like fruits and vegetables, by placing a sign nearby. There is no requirement for the labeling of irradiated food served by chain restaurants or hospitals that buy directly from distributors, nor any regulations for products that contain irradiated ingredients. Presently, the FDA allows food to be treated with three types of radiation -- gamma rays (伽马射线), high-energy electrons, and X rays -- and sets limits on doses, depending on the type of food. The principle is that the dose to be used for a certain type of food should not exceed the amount that is sufficient to kill most harmful insects and bacteria present in it. Different types of food, because of their molecular compositions, may require different doses of radiation.

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做出判断。如果该句提供的是正确信息，请选择A；如果该句提供的是错误信息，请选择 B：如果该句的信息文章中没有提及，请选择C。 {{B}} New Product Will Save lives{{/B}} Drinking water that looks clean may still contain bugs (虫子), which can cause illness. A small company called Genera Technologies has produced a testing method in three stages, which shows whether water is safe. The new test shows if water needs chemicals added to it to destroy anything harmful. It was invented by scientist Dr Adrian Patton, who started Genera five years ago. He and his employees have developed the test together with a British water company. Andy Headland. Genera's marketing director, recently presented the test at a conference in the USA and forecast good American sales for it. Genera has already sold 11 of its tests at $42,500 a time in the UK and has a further four on order. It expects to sell another 25 tests before the end of March. The company says it is the only test in the UK to be approved by the government. Genera was formed five years ago and until October last year had only five employees; it now employs 14. Mr Headland believes that the company should make around $19 million by the end of the year in the UK alone.

单选题 Plants in Desert Only special plants can survive the terrible climate of a desert, for these are regions where the annual range of the soil temperature can be over 75℃. Furthermore, during the summer there are few clouds in the sky to protect plants from the sun's ray. Another problem is the fact that there are frequently strong winds which drive small, sharp particles of sand into the plants, tearing and damaging them. The most difficult problem for all forms of plant life, however, is the fact that the entire annual rainfall occurs during a few days or weeks in spring. Grasses and flowers in desert survive from one year to the next by existing through the long, hot, dry season in the form of seeds. These seeds remain inactive unless the right amount of rain falls. If no rain falls, or if insufficient rain falls, they wait until the next year, or even still the next. Another factor that helps these plants to survive is the fact that their life cycles are short. By the time that the water from the spring rains disappears—just a few weeks after it falls—such plants no longer need any. The perennials have special features which enable them to survive as plants for several years. Thus, nearly all desert perennials have extensive root systems below ground and a small shoot system above ground. The large root network enables the plant to absorb as much water as possible in a short time. The small shoot system, on the other hand, considerably limits water loss by evaporation. Another feature of many desert perennials is that after the rainy season they lose their leaves in preparation for the long, dry season, just as trees in wetter climates lose theirs in preparation for the winter. This reduces their water loss by evaporation during the dry season. Then, in the next rainy season, they come fully alive once more, and grow new branches, leaves and flowers, just as the grasses and flowers in desert do.

单选题A complete change in policy is needed if relations are ever to improve.

单选题So far no one has been able to account for the cause of the accident.A. assessB. explainC. describeD. investigate

单选题These factors interact intimately and cannot be separated.

单选题For some {{U}}obscure{{/U}} reason, the simple game is becoming very popular. A. obvious B. major C. unclear D. minor

单选题Chicken Soup for the Soul: Comfort Food Fights Loneliness Mashed potatoes, macaroni and cheese, may be bad (51) your arteries, but according to a study in Psychological Science, they're good for your heart and emotions The study focuses on "comfort food" and (52) it makes people feel. "For me personally, food has always (53) a big role in my family, " says Jordan Troisi, a graduate student at the University of Buffalo, and lead author on the study. The study came out of the research program of his co-author Shira Gabriel. It has looked at non-human things (54) may affect human emotions. Some people reduce loneliness (55) bonding with their favorite TV show, (56) virtual relationships with a pop song singer or looking at pictures of loved ones. Troisi and Gabriel wondered if comfort food could have the same effect by making people think of their nearest and dearest. In one experiment, (57) make participants feel lonely, the researchers had them write for six minutes about a fight with (58) close to them. Others were given an emotionally neutral writing assignment. Then, some people in each group wrote about the experience of eating a comfort food and others wrote about eating a new food. (59) , the researchers had participants complete questions about their levels of loneliness. Writing about a fight with a close person made people feel (60) . But people who were generally secure in their relationships would feel less lonely by writing about a comfort food. "We have found that comfort foods are (61) associated with those close to us, " says Troisi. "Thinking about or consuming these foods later then serves as a reminder of those close others. " In their essays (62) comfort food, many people wrote about the experience of eating food with family and friends. In another experiment, eating chicken soup in the lab made people think more about relationships, but (63) they considered chicken soup to be a comfort food. This was a question they had been asked long (64) the experiment, along with many other questions, so they wouldn't remember it. Throughout everyone's daily lives they experience stress, often associated with our connections with others, Troisi says. "Comfort food (65) be an easy remedy for loneliness. /

单选题I try to read more books to broaden my knowledge.A. extendB. intendC. widenD. deepen

单选题Sleep also seems to be the time when the brain's two memory systems—the hippocampus(海马体) and the neocortex (新皮质)—"talk" with one other. Experiences that become memories are laid down first in the hippocampus, eliminating whatever is underneath. If a memory is to be retained, it must be shipped from the hippocampus to a place where it will endure—the neocortex, the wrinkled outer layer of the brain where higher thinking takes place. Unlike the hippocampus, the neocortex is a master at weaving the old with the new. And partly because it keeps incoming information at bay, sleep is the best time for the" undistracted" hippocampus to shuttle memories to the neocortex, and for the neocortex to link them to related memories. How can a piece of information become enduring memory in the brain?A. It must first go to the hippocampus for processing.B. It must be transferred to the neocoretex.C. It must eliminate the memory underneath it.D. It must be captured during the time of sleep.