单选题It is easy to misjudge the strength of the wind.

单选题I enjoyed the play--it had a clever plot and very funny dialogues.A. boringB. originalC. humorousD. long

单选题The first paragraph mentions three ways of activating the saliva in the mouth.

单选题Bees and Colour On our table in the garden we put a blue card, and all around this blue card we put a number of different grey cards. These grey cards are of all possible shades of grey and include white and black. On each card a watch-glass is placed. The watch-glass on the blue card has some syrup(果汁) in it, all the others are empty. After a short time bees find the syrup, and they come for it again and again. Then, after some hours, we take away the watch-glass of syrup which was on the blue card and put an empty one in its place. Now what do the bees do? They still go straight to the blue card, although there is no syrup there. They do not go to any of the grey cards, in spite of the fact that one of the grey cards is of exactly the same brightness as the blue card. Thus the bees do not mistake any shade of grey for blue. In this way we have proved that they do really see blue as a colour. We can find out in just the same way what other colours bees can see. It turns out that bees can see various colours, but these insects differ from us as regards their colour-sense in two very interesting ways. Suppose we train bees to come to a red card, and, having done so, we put the red card on the table in the garden among the set of different grey cards. This time we find that the bees mistake red for dark grey or black. They cannot distinguish between them. This means that red is not a cotour at all for bees; for them it is just dark grey or black. That is one strange fact; here is another. A rainbow is red on one edge, violet on the other. Outside the violet of the rainbow there is another colour which we cannot see at all. This colour beyond the violet, invisible to us, is called the ultra-violet. Although it is invisible, we know that the ultra-violet is there because it affects a photographic plate. Now, although we are unable to see ultra-violet light, bees can do so; for them ultra-violet is a colour. Thus bees see a colour which we cannot even imagine. This has been found out by training bees to come for syrup to various parts of a spectrum, or artificial rainbow, thrown by a prism on a table in a dark room. In such an experiment the insects can be taught to fly to the ultra-violet, which for us is just darkness.

单选题Our lives are intimately bound up with theirs.

单选题All gases and most liquids and solids expand when heated, but they do not expand {{U}}equally{{/U}}.

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 that 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 manual 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 the water from the spring rains disappears—just a few weeks after it falls—such plants no longer need any. The perennials (多年生植物) have special features that 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 short time. The small shoot system, on the other hand, considerably limits water loss by evaporation (蒸发). Another feature of many 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 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He has trouble understanding that other people judge him by his social skills and conduct .

单选题 Young Female Chimps Outlearn Their Brothers Young female chimps are faster and better learners than young male chimps, suggest a new study, echoing learning differences seen in human girls and boys. While young male chimps pass their time playing, young female chimps carefully study their mothers. As a result, they learn how to fish fortasty termite snacks over two years before the boys. Elizabeth Lonsdorf, now at Lincoln Park Zoo in Chicago, US, and colleagues at the University of Minnesota, Saint Paul, spent four years watching how young chimpanzees in the Gombe National Park in Tanzania learned "cultural behavior". The sex differences in learning behavior were "consistent and strikingly apparent", says the team. The researchers point out that similar differences are seen in human children with regard to skills such as writing. "A sex-based learning differences may therefore date back at least to the last common ancestor of chimpanzees and humans," they write in the journal Nature. Chimps make flexible tools from vegetation and then insert them into termite mounds extract them and then munch the termites clinging onto the tool. The researchers used video cameras to record this feeding behavior and found that each chimp mother had her own technique. Such as how she used tools of different lengths. Analysis of the six infants whose ages were known showed that girl chimps were an average of 31 months old when they succeeded in fishing out their termites, where the boy chimps were aged 58 months on average. Females were also more skillful at getting out more termites with every dip and used techniques similar to their mothers while males did not. Instead of studying their mothers, the boy chimps spent a significantly greater amount of time frolicking around the termite mound. Behaviors such as playing or swinging might help the male infants later in life when typically male activities like hunting or fighting for dominance become important, suggest the researchers. Lonsdorf adds that there are just two main sources of animal protein for chimps—the termites or colobus monkeys. "Mature males often hunt monkeys up trees. But females are almost always either pregnant or burdened with a clinging infants. This makes hunting difficult," she says. "Adult females spend more time fishing for termites than males." So becoming proficient at termite fishing could mean adult females eat better, "They can watch their offspring at the same time. The young of both sexes seem to pursue activities related to their adult sex roles at a very young age."

单选题{{B}}第三篇{{/B}} {{B}} Generation Gap{{/B}} A few years ago, it was fashionable to speak of a generation gap, a division between young people and their elders. Parents complained that children did not show them proper respect and obedience, while children complained that their parents did not understand them at all. What had gone wrong? Why had the generation gap suddenly appeared? Actually, the generation gap has been around for a long time. Many critics argue that it is built into the fabric of our society. One important cause of the generation gap is the opportunity that young people have to choose their own life styles. In more traditional societies, when children grow up, they are expected to live in the same area as their parents, to marry people that their parents know and approve of, and often to continue the family occupation. In our society, young people often travel great distances for their education, most out of the family home at an early age, marry or live or choose occupations different from those of their parents. In our upwardly mobile society, parents often expect their children to do better than they did: to find better jobs, to make more money, and to do all the things that they were unable to do. Often, however, the ambitions that parents have for their children are another cause of the division between them. Often they discover that they have very little in common with each other. Finally, the speed at which changes take place in our society is another cause of the gap between the generations. In a traditional culture, elderly people are valued for their wisdom, hut in our society the knowledge of a lifetime may Become obsolete overnight. The young and the old seem to live in two very different worlds, separated by different skills and abilities. No doubt, the generation gap will continue to be a feature of American life for some time to come. Its causes are rooted in the freedoms and opportunities of our society, and in the rapid pace at which society changes.

单选题You can arrive in Beijing earlier for the meeting ______ you don't mind taking the night train.A. ifB. unlessC. thoughD. until

单选题Colleges in the US have added a new subject, "green chemistry", (51) their curriculum(课程) today. " Green chemistry (52) how we can develop products that won't (53) the environment," explains Paul Anastas, director of Yale University's Center for Green Chemistry and Green Engineering. It opened (54) the beginning of this year. The American Chemical Society, (55) approves more than 600 college chemistry programs, only lists about a dozen that teach green chemistry. But that (56) s growing。 Cambridge College in Massachusens is (57) "an introduction to green chemistry" course this fall and is offering the nation's first bachelor's and master's (58) in green chemistry. The program will have classes in environmental science and even environmental (59) and policy. These subjects are not (60) taught to chemistry majors. Employers (61) the introduction of green chemistry. Businesses are increasingly seeking graduates (62) backgrounds in the subject (63) it can help them make or save money in the development and manufacturing of products. "We need people (64) can not only understand their place (65) , but also understand the worldwide perspective," said Adam Peterson, a chemicals division manager at Dow Coming Corp.

单选题Bill Gates: Unleashing Your Creativity I've always been an optimist and I suppose that is rooted in my belief that the power of creativity and intelligence can make the world a better place. For as long as I can remember, I've loved learning new things and solving problems. So when I sat down at a computer for the first time in seventh grade, I was hooked. It was a chunky old teletype machine and it could barely do anything compared to the computers we have today. But it changed my life. When my friend Paul Allen and I started Microsoft 30 years ago, we had a vision of "a computer on every desk and in every home," which probably sounded a little too optimistic at a time when most computers were the size of refrigerators. But we believed that personal computers would change the world. And they have. And after 30 years, I'm still as inspired by computers as I was back in seventh grade. I believe that computers are the most incredible tool we can use to feed our curiosity and inventiveness to help us solve problems that even the smartest people couldn't solve on their own. Computers have transformed how we learn, giving kids everywhere a window into all of the world's knowledge. They're helping us build communities around the things we care about and to stay close to the people who are important to us, no matter where they are. Like my friend Warren Buffett, I feel particularly lucky to do something every day that I love to do. He calls it "tap-dancing to work". My job at Microsoft is as challenging as ever, but what makes me "tap-dancing to work" is when we show people something new, like a computer that can recognize your handwriting or your speech, or one that can store a lifetime's worth of photos, and they say, "I didn't know you could do that with a PC!" But for all the cool things that a person can do with a PC, there are lots of other ways we can put our creativity and intelligence to work to improve our world. There are still far too many people in the world whose most basic needs go unmet. Every year, for example, millions of people die from diseases that are easy to prevent or treat in the developed world. I believe that my own good fortune brings with it a responsibility to give back to the world. My wife, Melinda, and I have committed to improving health and education in a way that can help as many people as possible. As a father, I believe that the death of a child in Africa is no less poignant or tragic than the death of a child anywhere else, and that it doesn't take much to make an immense difference in these children's lives. I'm still very much an optimist, and I believe that progress on even the world's toughest problems is possible and it's happening every day. We're seeing new drugs for deadly diseases, new diagnostic tools, and new attention paid to the health problems in the developing world. I'm excited by the possibilities I see for medicine, for education and, of course, for technology. And I believe that through our natural inventiveness, creativity and willingness to solve tough problems, we're going to make some amazing in all these area in my life.

单选题Everyone in the class participated in the farewell party.A. contributed toB. took pleasure inC. took part inD. enjoyed

单选题Loud noises can be irritating. A．hateful B．annoying C．stimulating D．painful

单选题He picked a book from the bookshelf and then commenced to read.

单选题If you think that you can never replace that priceless painting, don't Udespair/U. All is not lost!

单选题Would you please call my husband as soon as possible?A. contactB. consultC. phoneD. visit

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；如果该句的信息文中没有提及，请选择C。 　　　　　　　　　　　　　　　　　　　{{B}}Water -- the Issue of This Century{{/B}} The world is running short of fresh water. Populations are growing bigger and thirstier(渴的), with the result that fresh water is becoming increasingly scarce(缺乏). Half the world's wetlands have disappeared during the last century, while estimates suggest that water use will rise by 50% in the next 30 years. The World Bank report estimates that as much as half of the world's population,concentrated in Aflica. the Middle East and south Asia, will face "severe water shortages" by 2025. Local water conflicts and the IOSS of freshwater ecosystems appear large in some regions. A similar picture emerges from the globe's salt water regions. Three-quarters of the world's people may live within 100km of the sea in 2025, putting even more pressure on stretched coastal ecosystems. Two thirds of fisheries(渔业)are exploited at or beyond their sustainable limits,and half the world's coral reefs(珊瑚礁)may perish in 100 years. Almost 60% of coral reefs and 340/oo of fish species are at risk from human activities, the Bank says. The report concludes that there is ample evidence to Justify immediate and coordinated action to safeguard supplies and use water more efficiently. Fresh water consumption is rising quickly, and the availability of water in some regions is likely to become one of the most pressing issues of the 21st century. A third of the world's population -- around two billion people -- live in countries that are experiening moderate to high water shortages. That proportion could rise to half or more in the next 30 years unless institutions(制度)change to ensure better conservation and allocation of water. China is one country where the portents(征兆)are gloomy, the most water-stressed country in East Asia. China is exploiting 44% of its usable water,a figure projected to rise to 60% by 2020. Primary withdrawal of water of more than 60% is widely considered by water experts to exceed the environmental carrying capacity of a river basin system. Although China's total use appears still to be reasonable, it has several basins that are severely stressed environmentally. Withdrawals exceed environmental limits in Afghanistan and Pakistan, and will exceed them in India by 2020. In the Middle East and North Africa, only Morocco has unexploited water resources. The rest hlave exceeded environmental limits and many are mining aquifers (蓄水层) -- bodies of water-bearing rock -- the report says.

单选题We had trouble finding a Upure /Uwater supply