单选题The boy regretted having spent so much time playing when he ______ A. should have studied B. had studied C. was to study D. must study

单选题Theteacherwasa_______womanwhodidherbest.

单选题The seller signed the ______, promising to ship the goods before the end of July.

单选题Those nations that interfere in the internal affairs of another nation should be ______ condemned. A. commonly B. actually C. uniquely D. universally

单选题Passer-by: ______? Loeal resident: Yes, there's one near the end of the street. It's behind the church. A. Hello. sir. Where's the bus station B. Excuse me. Is there a parking lot anywhere around here C. Excuse me, sir. How can I find the way to the police station D. Which building is the Department of Immigration, please

单选题How often one hears children wishing they were grown up, and old people wishing they were young again. Each age has its pleasures and its pains, and the happiest person is the one who enjoys what each age gives him without wasting his time in useless regrets. Childhood is a time when there are few responsibilities to make life difficult. If a child has good parents, he is fed, looked after and loved, whatever he may do. It is impossible that he will ever again in his life be given so much without having to do anything in return. In addition, life is always presenting new things to the child—things that have lost their interest for older people because they are too wellknown. But a child has his pains: he is not so free to do what he wishes to do; he is continually being told not to do things, or being punished for what he has done wrong. When the young man starts to earn his own living, he can no longer expect others to pay for his food, his clothes, and his room, but has to work if he wants to live comfortably. If he spends most of his time playing about in the way that he used to as a child, he will go hungry. And if he breaks the laws of society as he used to break the laws of his parents, he may go to prison. If, however, he works hard, keeps out of trouble and has good health, he can have the great happiness of building up for himself his own position in society.

单选题It was the people's courage that brought them ______ the war.

单选题{{B}}Passage Two{{/B}} Genetic engineering holds great potential payoffs for farmers and consumers by making crops resistant to pests, diseases, and even chemicals used to kill surrounding weeds; but new research raises concerns that altering crops to withstand such threats may pose new risks--from none other than the weeds themselves. This is due to the weeds' ability to acquire genes from the neighboring agricultural crops. Researchers found that when a weed cross-breeds with a farm-cultivated relative and thus acquires new genetic traits--possibly including artificial genes engineered to make the crop hardier--the hybrid weed can pass along those traits to future generations. "The result may be very hardy, hard-to-kill weeds," said Allison Snow, a plant ecologist at Ohio State University in Columbus who conducted the experiments over the past six years along with two colleagues. They presented their results last week at the annual meeting of the Ecological Society of America in Madison, Wisconsin. The findings suggest that genetic engineering done with the aim of improving crops--growing the new genetic traits such as resistance to herbicides or pests-- could ultimately have unintended and harmful consequences for the crops if weeds acquire the same trait and use it to out-compete the crops. "Gene movement from crops to their wild relatives is an ongoing process that can be ultimately harmful to crops," said Snow. The results of the experiments challenge a common belief that hybrids gradually die out over several generations, Snow explained. "There has been an assumption that crop genes wouldn't persist in crop-weed hybrids" because hybrids are thought to be less successful at reproducing, she said. However, Snow's research contradicted this assumption: Hybrid wild radishes survived in all six generations that were grown since the study began. Although the genetic traits the scientists monitored were natural and not genetically engineered, the findings nonetheless suggest that artificial improvements introduced into crops through genetic engineering could spread to weeds and become permanent traits of the weed population. So strengthened, the weeds may pose a serious risk to the long-term health of agricultural crops. The danger exists in a number of crop plants--including rice, sunflower, sorghum, squash, and carrots--that are closely related to weeds with which they compete. Snow is concerned that the transfer of genes from crops to related weeds could rapidly render many herbicides (chemicals which kill weeds) ineffectual. That situation, she said, would be much like bacterial diseases acquiring resistance to antibiotics. Because plant hybrids arise in a single generation, however, it could happen much more quickly; "Modern agriculture is heavily dependent on herbicides," she said, "so people will notice when those don't work anymore."

单选题I feel quite confident in ______ Mr. Jackson to you for the vacant post of research assistant.

单选题The engine has broken down and the boat is ______.

单选题The candidate has complied with all the requirements set by the university; this institution, therefore awards her the degree of Master of Arts.

单选题All of the following whales belong to the suborder of Odontoceti EXCEPT ______.

单选题The conference appealed to the international community to jointly_____the issue of global warming.

单选题______ you ______ further problems with your printer, contact your dealer for advice. A. If...had B. Have...had C. Should...have D. In case...had

单选题Women, according to Chairman Mao, hold up half the sky—but in California some are better rewarded for this effort than others. According to a new study from the Public Policy Institute of California, Asian women born in the United States outstrip all their sisters in terms of earning power. The average hourly wage for American-born Asian ladies in 2001 (the latest year with reliable figures) was $19.30, with American-born whites coming next. On the bottom rungs of the ladder came Latinas: if born abroad, they earned a mere $10.40 an hour (though this was comfortably above California's then $6.25 minimum wage); if born in America, they managed $15.10 an hour. Education is the biggest reason for the ethnic disparities. Some 55% of California's American-born Asian women have at least a bachelor's degree, and an impressive 84% of them either have jobs or are looking for them. By contrast, only 14% of American-born Hispanic women have a bachelor's degree and only 74% of them are in the labour market. Meanwhile, Latinas born abroad are often condemned to low-paying jobs by an even inefficient education or a poor knowledge of English. Much the same can be said of Asian women born in South-East Asia, a category that includes refugees from Laos, Vietnam and Cambodia. The institute calculates that they earned an average of $15.80, almost $1 less than other foreign-born Asians. But education is not the only factor in play for California's women. Larger families make it more difficult for Latinas to go out to work in the first place; blacks often live too far away to commute to well-paid jobs; and just as Asians may benefit from high expectations, so other groups may suffer from low ones. The institute makes an attempt, heroic or politically correct, to adjust for such factors, imagining, for example, that a foreign-born Latina has the same family structure, education and place of residence as the average Californian woman. That brings the average wage for foreign-born Latinas up to a more respectable $15.20; yet American-born Asians still rule the roost. But before the golden girls get too happy, the institute reckons that Californian women of all sorts tend to earn roughly 20% less than their menfolk do.

单选题 What makes a great high school? Americans think a lot of things do, from outstanding academics or a supportive environment for students to a great football or basketball team. Still, pretty much everyone agrees teaching and learning are central to the mission. High schools are expected to prepare students for further education, work, or the military and eliminate the large gaps in achievement separating different ethnic and income groups of students. These are sensible goals. While there are many great high schools among the nearly 22,000 across the country, too many are still not getting the job done. Only about half of African-American and Hispanic students finish high school on time. Meanwhile, the National Assessment of Education Progress tests, often referred to as "the nation's report card," show significant achievement gaps separating white students from black and Hispanic high school students. These are not small differences but rather vast gaps that crush opportunity and tear at our nation's social contract. Leave aside the intrinsic value of being an educated citizen; there are practical effects as well. In 2005, the mean annual earnings were about ＄20,000 for a high school dropout but ＄54,000 for someone with a bachelor's degree. And those differences are growing wider, not lessening, as our economy becomes more knowledge and skills based. In 1975, a high school dropout earned about half as much as a college graduate, compared with about one third today. This is why U.S. News set some clear criteria for academic quality in its new ranking of American high schools. These criteria mean a lot of schools don't measure up-only 505 schools nationwide earned a silver or gold medal this year. The list illustrates at once the promise and the challenge for high schools today. Only about 1 in 8 of the schools on this list serves a student population that is more than 50 percent low income, and only about 1 in 5 has a majority of nonwhite students. Meanwhile, about 1 in 5 selects students based on academic merit, something that obviously boosts the chances of meeting the criteria. Because the U.S. News list uses more data to judge schools, it paints a clearer picture. Of course, no list is perfect. For instance, it is difficult to account for high school graduation rates because states calculate them in different ways. But this one better reflects what policymakers and parents want from high schools, as well as the challenge our nation faces to make our high schools as good as they need to be.

单选题Shopping for clothes is not the 1 experience for a man as it is for a woman. A man goes shopping because he needs something. His purpose is settled and decided in 2 He knows what he wants, and his objective is to find it and buy it; the price is a secondary 3 : All men simply walk into a shop and ask for what they want. If the shop has it in 4 , the salesman promptly produces it, and the business of 5 it on proceeds at once. And if all 6 well, the deal can be and often is completed in less than five minutes, with no chat and to everyone"s satisfaction. Now how does a woman go out buying clothes? Her shopping is not always 7 on needs. She has 8 fully made up her mind what she wants, and she is only "having a look 9 " She is always open to 10 , indeed she sets great store by what the salesman tells her, even by what companions tell her. She will try on any number of things. Uppermost in her mind 11 the thought of finding something that everyone thinks suits her. 12 to a lot of jokes, most women have an excellent sense of value when they buy clothes. They are always in the lookout for the unexpected 13 Faced with a roomful of dresses, a woman may easily 14 an hour going from one rail to another, to and fro, often retracing her steps, before selecting the dresses she wants to try on. It is a laborious process, but apparently an 15 one. Most dress shops provide chairs for the waiting husbands.

单选题It is believed that nomadic ancestors considered bumper harvests as bounty form the "God of Sun" and natural disasters as punishment.