单选题The police stopped me the other day as I was driving home, because I was ______ the speed limit.

单选题Historically, the spread, prevalence, and very existence of contagious disease have wholly depended on the growth and concentration of human populations.【R1】______And though the last century has witnessed substantial worldwide success in combating many past scourges—such as polio and smallpox—infectious diseases still claim more lives than any other group of diseases. The prevailing demographic trends continue to create a crowded human " medium" that both invites and is vulnerable to infection. The share of humanity living in cities with more than 1 million people has surged from less than 5 percent in 1900 to nearly 40 percent today, creating the ideal setting for the resurgence of old infectious diseases as well as the development of new ones.【R2】______ Overcrowding—the increased proximity of susceptible individuals—is a principal risk factor for the incidence and spread of all major infectious diseases, including tuberculosis, dengue fever, malaria, and acute respiratory illnesses, which are unable to spread and survive in low population densities.【R3】______ Aside from sheer growth and increasing density, the urbanization under way in developing nations is often accompanied by deteriorating health indicators and increased exposure to disease risk factors. Access to clean water, good hygiene, and adequate housing are sorely lacking in developing nations. As a result, waterborne infections such as cholera and other diarrheal diseases account for 90 percent of all infectious diseases in developing countries—and 40 percent of all deaths in some nations.【R4】______ In both industrial and developing nations, incidences of a wide range of infectious diseases, including tuberculosis, diarrheal diseases, and HIV/AIDS, are considerably higher in urban slums— where poverty and compromised health define the way of life—than in the rest of the city.【R5】______A. Key disease carriers, such as insects and rats, thrive in crowded urban settings, further facilitating spread.B. The unprecedented population densities in fourteenth-century Europe, for example, led to the plague outbreak that claimed the lives of one fourth of the population.C. Although these infections are easily preventable if adequate water and sanitation are available, the vast majority of the world's population is lifelong victims.D. While new global markets have created unprecedented economic opportunities and growth, the health risks of our increasingly interconnected and fast-paced world continue to grow.E. Pathogens can more readily establish in large populations, since all infectious diseases require a critical number of vulnerable individuals in order to take root and spread.F. These areas can serve as a perpetual reservoir of disease or disease vectors, placing other parts of the city at risk of an outbreak and allowing the disease to continue evolving, often into a deadlier strain.

单选题3 Certainly no creature in the sea is odder than the common sea cucumber. All living creatures, especially human beings, have their peculiarities, but everything about the little sea cucumber seems unusual. What else can be said about a bizarre animal that" among other eccentricities, eats mud, feeds almost continuously day and night but can live with- out eating for long periods, and can be poisonous but is considered supremely edible by gourmets? For some fifty million years, despite all its eccentricities, the sea cucumber has sub- sisted on its diet of mud. It is adaptable enough to live attached to rocks by its tube feet, under rocks in shallow water, or on the surface of mud flats. Common in cool water on both Atlantic and Pacific shores, it has the ability to suck up mud or sand and digest whatever nutrients are present. Sea cucumbers come in a variety of colors, ranging from black to reddish-brown to sand-colored and nearly white. One form even has vivid purple tentacles. Usually the crea- tures are cucumber-shaped--hence their name and because they are typically rock inhabitants, this shape, combined with their flexibility, enables them to squeeze into crevices where they are safe from predators and ocean currents. Although they have voracious appetites, eating day and night, sea cucumbers have the capacity to become quiescent and live at a low metabolic rate--feeding sparingly or not at all for long periods, so that the marine organisms that provide their food have a chance to multiply. If it were not for this faculty, they would devour all the food available in a short time and would probably starve themselves out of existence. But the most spectacular thing about the sea cucumber is the way it defends itself. Its major enemies are fish and crabs. When attacked, it squirts all its internal organs into the water. It also casts off attached structures such as tentacles. The sea cucumber will eviscerate and regenerate itself if it is attacked or even touched: it will do the same if the surrounding water temperature is too high or the water becomes too polluted.

单选题It is well known that the first ______ can only work hard planting young trees for a new business, while the following people may obtain the successful fruits.

单选题{{B}}Passage One{{/B}} As we have seen in earlier chapters, the American definition of success is largely one of acquiring wealth and a higher material standard of living. It is not surprising, therefore, that Americans have valued education for its monetary value. The belief is widely spread in the United States that the more schooling people have, the more money they will earn when they leave school. The belief is strongest regarding the desirability of an undergraduate university degree, or a professional degree such as medicine or law following the undergraduate degree. The money value of graduate degrees in "non-professional" fields such as art, history, or philosophy is not as great. This belief in the monetary value of education is supported by statistics on income. Ben Wattenberg, a social scientist, estimated that in the course of a lifetime a man with a college degree in 1972 would earn about ￥380,000 more than a man with just a high school diploma. Perhaps this helps to explain survey findings which showed that Americans who wished they had led their lives differently in some way regretted most of all that they did not get more education. The regret is shared by those who have made it to the top and by those who have not. Journalist Richard Reeves quotes a black worker in a Ford automobile factory. When I was in the ninth grade, I was getting bad grades and messing around. My father came home in the kitchen one night with a pair of Ford work pants and he threw them in my face. "Put these on," he said, "because you're going to be wearing them the rest of your life if you don't get an education." Douglas Fraser, the president of the United Auto Workers Union, regretted not finishing high school so much that he occasionally lied about it. He told Richard Reeves about his pride in graduating from high school, but then a few minutes later he said, "I wasn't telling the truth about high school. I never finished. I quit in the twelfth grade to take a job. It's funny after all these years, I still lie about it. Because the fact is, I still think it was a stupid thing to do. I should have finished my education." Even a man like Fraser, a nationally known and successful leader, was troubled by regrets that he did not climb higher on the educational ladder.

单选题He spends a lot of time going through football magazines, making intricate lists, and working out comprehensive statistics.

单选题In a recent book entitled The Psychic Life of Insects, Professor Bouvier says that we must be careful not to credit the little winged fellows with intelligence when they behave in what seems like an intelligent manner. They may be only reacting. I would like to confront the professor with an instance of reasoning power on the part of an insect which cannot be explained away in any other manner. During the summer of 1899, while I was at work on my doctoral thesis, we kept a female wasp at our cottage. It was more like a child of our own than a Wasp, except that it looked more like a wasp than a child of our own. That was one of the ways we told the difference. It was still a young wasp when we got it (thirteen or fourteen years old) and for some time we could not get it to eat or drink, it was so shy. Since it was a female we decided to call it Miriam, but soon the children"s nickname for it— "Pudge" —became a fixture, and "Pudge" it was from that time on. One evening I had been working late in my laboratory fooling around with some gin and other chemicals, and in leaving the room I tripped over a nine of diamonds which someone had left lying on the floor and knocked over my card index which contained the names and addresses of all the larvae worth knowing in North America. The cards went everywhere. I was too tired to stop to pick them up that night, and went sobbing to bed, just as mad as I could be. As I went, however, I noticed the wasp was flying about in circles over the scattered cards. "Maybe Pudge will pick them up," I said half laughingly to myself, never thinking for one moment that such would be the case. When I came down the next morning Pudge was still asleep in her box, evidently tired out. And well she might have been. For there on the floor lay the cards scattered all about just as I had left them the night before. The faithful little insect had buzzed about all night trying to come to some decision about picking them up and arranging them in the boxes for me, and then had figured out for herself that, as she knew practically nothing of larvae of any sort except wasp larvae, she would probably make more of a mess of rearranging them than if she had left them on the floor for me to fix. It was just too much for her to tackle, and, discouraged, she went over and lay down in her box, where she cried herself to sleep. If this is not an answer to Professor Bouvier"s statement, I do not know what is.

单选题______sleep is crucial to the health of adults, new research suggests that lack of sleep may affect teens' health, too.

单选题The explorers came forward with gifts of ducks and flour-cakes and______ troughs of water tor the horses to drink.(2013年厦门大学考博试题)

单选题Can you explain this ______ of ten years in your job history which you have not accounted for? A.interruption B.gap C.split D.paring

单选题The small building was marked with a modest brass ______, stating the name and the business of the occupiers. A. plaque B. plateau C. plague D. plaster

单选题The official was arrested for inability to ______ all his fortune he has enjoyed. A. clarify B. intensify C. verify D. justify

单选题The performance was staged by a group of ______ who have been studying dramatics as a hobby.

单选题In recent years, railroads have been combining with each other, merging into super systems, causing heightened concerns about monopoly. As recently as 1995, the top four railroads accounted for under 70 percent of the total ton-miles moved by rails. Next year, after a series of mergers is completed, just four railroads will control well over 90 percent of all the freight moved by major rail carriers. Supporters of the new super systems argue that these mergers will allow for substantial cost reductions and better coordinated service. Any threat of monopoly, they argue, is removed by fierce competition from trucks. But many shippers complain that for heavy bulk commodities traveling long distances, such as coal, chemicals, and grain, trucking is too costly and the railroads therefore have them by the throat. The vast consolidation within the rail industry means that most shippers are served by only one rail company. Railroads typically charge such "captive" shippers 20 to 30 percent more than they do when another railroad is competing for the business. Shippers who feel they are being overcharged have the right to appeal to the federal government"s Surface Transportation Board for rate relief, but the process is expensive, time consuming, and will work only in truly extreme cases. Railroads justify rate discrimination against captive shippers on the grounds that in the long run it reduces everyone"s cost. If railroads charged all customers the same average rate, they argue, shippers who have the option of switching to trucks or other forms of transportation would do so, leaving remaining customers to shoulder the cost of keeping up the line. It"s theory to which many economists subscribe, but in practice it often leaves railroads in the position of determining which companies will flourish and which will fail. "Do we really want railroads to be the arbiters of who wins and who loses in the marketplace?" asks Martin Bercovici, a Washington lawyer who frequently represents shipper. Many captive shippers also worry they will soon be hit with a round of huge rate increases. The railroad industry as a whole, despite its brightening fortunes, still does not earn enough to cover the cost of the capital it must invest to keep up with its surging traffic. Yet railroads continue to borrow billions to acquire one another, with Wall Street cheering them on. Consider the 1.02 billion bid by Norfolk Southern and CSX to acquire Conrail this year. Conrail"s net railway operating income in 1996 was just 427 million, less than half of the carrying costs of the transaction. Who"s going to pay for the rest of the bill? Many captive shippers fear that they will, as Norfolk Southern and CSX increase their grip on the market.

单选题Careful planning and hard work will______our final success.

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单选题Other modern industrial nations such as Japan, Germany and France have managed A(all along) to thrive B(with mere fractions) of C(man-made coolness) used in the US, and D(precious little of that) in private dwellings.

单选题This is only a ______ agreement: nothing serious concluded yet by far.