单选题This crop has similar qualities to the previous one, ______ both wind-resistant and adapted to the same type of soil. A. being B. been C. to be D. having been

单选题Every man in this country has the right to live where he wants to ______ the color of his skin. A. with the exception of B. in the light C. by virtue of D. regardless of

单选题It was lack of money, not of effort, ______ defeated their plan.A．whichB．asC．thatD．what

单选题We are making good progress, but we must not______until we have achieved our objective.

单选题The (people native) to the northwest coast of North American have long (be known) (for) wood carvings (of) stunning beauty and extraordinary quality.

单选题You could be ______ many dangers by traveling alone in that area. A. subject to B. immune to C. sensitive to D. resistant to

单选题He stated that unless I ceased harassing Sir William he would not be prepared to defend me.

单选题Generations of Americans have been brought up to believe that a good breakfast is one of life's essentials. Eating breakfast at the start of the day, we have all been told, is as necessary as putting gasoline in the family car before starting a trip. But for many people the thought of food first thing in the morning is by no means a pleasure. So despite all the efforts, they still take no breakfast. Between 1977 and 1983, the latest years for which figures are available, the number of people who didn't have breakfast increased by 33 percent—from 8. 8 million to 11. 7 million—according to the Chicago-based Market Research Corporation of America． For those who feel pain or guilt about not eating breakfast, however, there is some good news. Several studies in the last few years indicate that, for adults especially, there may be nothing wrong with omitting breakfast. "Going without breakfast does not affect performance. " said Arnold E. Bender, the former professor of nutrition at Queen Elizabeth College in London, "nor does giving people breakfast improve performance. " Scientific evidence linking breakfast to better health or better performance is surprisingly inadequate, and most of the recent work involves children, not adults. "The literature," says one researcher, Dr. Ernesto Pollitt at the University of Texas, "is poor".

单选题{{B}}Text 3{{/B}} It's not only humans that flourish in large settlements. Some ants find urban life so accommodating that their populations explode and they form supercolonies in cities. "One of the most common house ant species might have been built for living in some of the smallest spaces in a forest, but the ants have found ways to take advantage of the comforts of city living," Purdue University said in a statement. Grzegorz Buczkowski, a Purdue University research assistant professor of entomology, discovered odorous house ants live in supercolonies, creating complex networks entomologists have never seen with the species before now. He found that odorous house ant colonies become larger and more complex as they move from forest to city and act somewhat like an invasive species, the university said. "The ants live about 50 to a colony with one queen in forest settings but explode into supercolonies with more than 6 million workers and 50 000 queens in urban areas," the university explained. "This is a native species that's doing this," said Buczkowski, whose results are published in the early online version of the journal Biological Invasions. "Native ants are not supposed to become invasive. We don't know of any other native ants that are outcompeting other species of native ants like these," Buczkowski said. Odorous house ants live in hollow acorn shells in the forest. They're called odorous because they have a coconut (椰子)-or rum-like smell when crushed. They're considered one of the most common house ants, Purdue said. In semi-natural areas that are a cross of forest and urban areas, such as a park, Buczkowski said he observed colonies of about 500 workers with a single queen. "It's possible that as the ants get closer to urban areas they have easier access to food, shelter and other resources," he said. "In the forest, they have to compete for food and nesting sites," Buczkowski said. "In the cities, they don't have that competition. People give them a place to nest, food to eat. " Buczkowski observed the ants in three different settings on and around the Purdue campus. He said it might be expected that if the odorous house ants were able to multiply into complex colonies, other ants would do the same. But Buczkowski found no evidence that other ants had adapted to new environments and evolved into larger groups as the odorous house ants have, Purdie said. "It's possible that odorous house ants are better adapted to city environments than other ant species or that they had somehow outcompeted or dominated other species," he said. "This raises a lot of questions we'd like to answer. " Buczkowski said understanding why the supercolonies form could lead to better control of the pests in homes, as well as ensuring that they don't outcompete beneficial species. Future studies on odorous house ants will include studying the ant's genetics and trying to understand the effects of urbanization of odorous house ants, Purdue said.

单选题A: We just came back from hoenix. And we had the best vacation is years. B: ______ I'm glad to hear it.

单选题The professionals, according to the text, have made a mistake in

单选题Consumers are being confused and misled by the hodge-podge of environmental claims made by household products, according to a "green labeling" study published by Consumers International Friday. Among the report"s more outrageous findings—a German fertilizer described itself as "earthworm friendly", a brand of flour said it was "non-polluting" and a British toilet paper claimed to be "environmentally friendlier". The study was written and researched by Britain"s National Consumer Council (NCC) for lobby group Consumer International. It was funded by the German and Dutch governments and the European Commission. "While many good and useful claims are being made, it is clear there is a long way to go in ensuring shoppers are adequately informed about the environmental impact of products they buy," said Consumers International director Anna Fielder. The 10-country study surveyed product packaging in Britain, Western Europe, Scandinavia and the United States. It found that products sold in Germany and the United Kingdom made the most environmental claims on average. The report focused on claims made by specific products, such as detergent insect sprays and by some garden products. It diet not test the claims, but compared them to labeling guidelines set by the International Standards Organization (ISO) in September, 1999. Researchers documented claims of environmental friendliness made by about 2,000 products and found many too vague or too misleading to meet ISO standards. "Many products had specially-designed labels to make them seem environmentally friendly, but in fact many of these symbols mean nothing," said report researcher Philip Page. "Laundry detergents made the most number of claims with 158 household cleaners were second with 145 separate claims, while paints were third on our list with 73. The high numbers show how very confusing it must be for consumers to sort the true from the misleading." he said. The ISO labeling standards ban vague or misleading claims on product packaging, because terms such as "environmentally friendly" and "non-polluting" cannot be verified. "What we are now pushing for is to have multinational corporations meet the standards set by the ISO." said Page.

单选题{{B}}Text 2{{/B}} Information technologists have dreamt for decades of making an electronic display that is as good as paper: cheap enough to be pasted on to wails and billboards, clear enough to be read in broad daylight, and thin and flexible enough to be bound as hundreds of flippable leaves to make a book. Over the past few years they have got close. In particular, they have worked out how to produce the display itself, by sandwiching tiny spheres that change colour in response to an electric charge inside thin sheets of flexible, transparent plastic. What they have not yet found is a way to mass-produce flexible electronic circuitry with which to create that charge. But a paper just published in the Proceedings of the National Academy of Sciences suggests that this, too, may be done soon. The process described by John Rogers and his colleagues from Bell Laboratories, an arm of Lucent Technologies, in New Jersey, and E Ink Corporation, in Cambridge, Massachusetts, starts with E Ink's established half-way house towards true electronic paper. This is based on spheres containing black, liquid dye and particles of white, solid pigment. The pigment particles are negatively charged, so they can be pushed and pulled around by electrodes located above and below the sheet. The electrodes, in turn, are controlled by transistors under the sheet. Each transistor manipulates a single picture element (pixel), making it black or white. The pattern of pixels, in turn, makes up the picture or text on the page. The problem lies in making the transistors and connections. Established ways of doing this, such as photolithography, use silicon as the semiconductor in the transistors. That is all right for applications suck as pesters. It is too fragile and too expensive, though, for genuine electronic paper—which is why cheap and flexible electronic components are needed. For flexibility, Dr Rogers and his colleagues chose pentacene as their semiconductor, and gold as their wiring. Pentacene is a polymer whose semiconducting properties were discovered only recently. Gold is the most malleable metal known, and one of the best electrical conductors. Although it is pricey, so little is needed that the cost per article is tiny. To make their electronic paper the researchers started with a thin sheet of Mylar, a tough plastic, that was coated with indium-tin oxide (ITO), a transparent electrical conductor. To carve this conductor into a suitable electric circuit, they used an innovation called microcontact printing lithography. This trick involves printing the pattern of the circuit on to the ITO using a rubber stamp. The "ink" in the process is a solvent-resistant chemical that protects this part of the ITO while allowing the rest to be dissolved.

单选题The phrase "function in the disservice of one another" ( Line 7, Par

单选题You will find a tall building ______ the end of the road. A．on B．in C．by D．at

单选题It was in 1777 ______ Vermont, threatened with invasion, declared itself an independent commonwealth.

单选题Long-suffering couples take heart. There is a good reason for those endless arguments in the front of the car: men and women use different parts of the brain when they try to find their way a-round, suggesting that the strategies they use might also be completely different. Matthias Riepe and his colleagues at the University of Ulm in Germany asked 24 healthy volunteers—half of them men, half women—to find their way out of three virtual-reality mazes displayed on video goggles. Meanwhile, the researchers monitored the volunteers" brain activity using a functional magnetic resonance imaging(fMRI)scanner. This showed that men and women called on strikingly different brain areas to complete the task. "I didn" t expect it to be so dramatic," says Riepe. Previous studies have been shown that women rely mainly on landmarks to find their way. Men use these cues too, but they also use geometric cues, such as the angle and shape of a wall or a corner. Such studies also suggest that men navigate their way out of unfamiliar spaces more quickly, as Riepe found in his study, too. Riepe discovered that both men and women used parts of the parietal cortex towards the top of the brain, the right side of the hippocampus and a few other well-established areas to find their way out. Neuroscientists think that the parietal regions help translate what the eyes see into information about where the body is in space, while the hippocampal region helps process how objects are arranged. But other regions seemed to be exclusively male or female. The men engaged the left side of their hippocampus, which the researchers say could help with assessing geometry or remembering whether they have already visited a location. The women, by contrast, recruited their right frontal cortex. Riepe says this may indicate that they were using their "working memory" , trying to keep in mind the landmarks they had passed. "It fits very well with the animal studies," says Riepe. He points out that there seem to be similar differences in rats. For example, damage to the frontal lobe will impair a female" s sense of direction, but not a male" s.

单选题According to a survey, which was based on the responses of over 188,000 students, today's traditional-age college freshmen are "more materialistic and less altruistic (利他主义的) than at any time in the 17 years of the poll. Not surprising in these hard times, the students' major objective "is to be financially well off. Less important than ever is developing a meaningful philosophy of life." It follows then that today the most popular course is not literature or history but accounting. Interest in teaching, social service and the "altruistic" fields is at a low. On the other hand, enrollment in business programs, engineering and computer science is way up. That's no surprise either. A friend of mine (a sales representative for a chemical company) was making twice the salary of her college instructors in her first year on the job—even before she completed her two-year associate degree. While it's true that we all need a career, it is equally true that our civilization has accumulated an incredible amount of knowledge in fields far removed from our own and that we are better for our understanding of these other contributions—be the scientific or artistic. It is equally true that, in studying the diverse wisdom of others, we learn how to think. More important, perhaps, education teaches us to see the connections between things, as well as to see beyond our immediate needs. Weekly we read of unions who went on strike for higher wages, only to drive their employer out of business. No company; no job. How shortsighted in the long run. But the most important argument for a broad education is that in studying the accumulated wisdom of ages, we improve our moral sense. I saw a cartoon recently which shows a group o businessmen looking puzzled as they sit around a conference table; one of them is talking on the intercom (对讲机) : "Miss Baxter," he says, "could you please send in someone who can distinguish right from wrong?" From the long-term point of view, that's what education really ought to be about.

单选题When he traveled abroad, Mr. Smith ______.