单选题We sometimes think humans are uniquely vulnerable to anxiety, but stress seems to affect the immune defenses of lower animals too. In one experiment, for example, behavioral immunologist Mark Laudenslager, at the University of Denver, gave mild electric shocks to 24 rats. Half the animals could switch off the current by turning a wheel in their enclosure, while the other half could not. The rats in the two groups were paired so that each time one rat turned the wheel it protected both itself and its helpless partner from the shock. Laudenslager found that the immune response was depressed below normal in the helpless rats but not in those that could turn off the electricity. What he has demonstrated, he believes, is that lack of control over an event, not the experience itself, is what weakens the immune system. Other researchers agree. Jay Weiss, a psychologist at Duke University School of Medicine, has shown that animals who are allowed to control unpleasant stimuli don' t develop sleep disturbances or changes in brain chemistry typical of stressed rats. But if the animals are confronted with situations they have no control over, they later behave passively when faced with experiences they can control. Such findings reinforce psychologists' suspicions that the experience or perception of helplessness is one of the most harmful factors in depression. One of the most startling examples of how the mind can alter the immune response was discovered by chance. In 1975 psychologist Robert Ader at the University of Rochester School of Medicine conditioned mice to avoid saccharin by simultaneously feeding them the sweetener and injecting them with a drug that while suppressing their immune systems caused stomach upsets. Associating the saccharin with the stomach pains, the mice quickly learned to avoid the sweetener. In order to extinguish this dislike for the sweetener, Ader re-exposed the animals to saccharin, this time without the drug, and was astonished to find that those mice that had received the highest amounts of sweetener during their earlier conditioning died. He could only speculate that he had so successfully conditioned the rats that saccharin alone now served to weaken their immune systems enough to kill them.

单选题You will hear three dialogues or monologues. Before listening to each one, you will have 5 seconds to read each of the questions which accompany it. While listening, answer each question by choosing A, B, C or D. Questions 11—13 are based on the following dialogue.

单选题 The ostrich, the largest bird in the world at present, lives in the drier regions of Africa outside the actual deserts．Because of its very long，powerful legs and the floating effect of its extended wings，it is able to run at great speed over considerable distances． The female ostrich normally produces about twenty eggs every rainy season． When the female ostrich begins to lay her eggs, however, she does not begin in her own nest．Instead she goes off in search of the nests of neighboring females and laystwo or three eggs in each of them．By the time she has laid eight or nine eggs，she returns and lays the rest in her own nest． Because of the size of the eggs, the female ostrich cannot lay more than one every two days，so it takes her three weeks to finish laying in her own nest．During that period, she spends a lot of time away from her nest looking for food．And while she is off her nest, other females visit it to lay their eggs amongst hers．By the time she is ready to sit on the eggs to hatch them, there could be up to thirty eggs in her nest, over half of which are not her own． The female ostrich can comfortably cover only about twenty eggs when she is sitting on the nest, so before settling down she pushes the surplus ten or so eggs out of the nest．The rejected eggs, however, never include any of her own．Each female is remarkably consistent in the size and shape of the eggs she produces, so it is not difficult for her to distinguish her own from those of strangers． Of all the eggs laid by a colony of ostriches, only a very small number hatch into young birds．There are times when nests are left unprotected, for there are too few males to sit on all the nests at night．Thus there are ample opportunities for their natural enemies to raid the nests and eat the eggs．In fact，nearly 80% of the nests are destroyed．But even if a particular female's nest suffers this fate, there is a good chance that one or two of her eggs will be hatched in the nest of one of her neighbors．

单选题[此试题无题干]

单选题When we think of Hollywood—a term I use loosely to describe American movie production in general, not simply films made in Los Angeles — we think of films aimed at musing audiences and making money for producers. During the early years of the new century, as workers won their demands for higher wages and a shorter working week, leisure assumed an increasingly important role in everyday life. Amusement parks, professional baseball games, nickelodeons, and dance halls attracted a wide army of men and woman anxious to spend their hard-earned dollars in the pursuit of fun and relaxation. Yet of all these new cultural endeavours, films were the most important and widely attended source of amusement. For a mere five or ten cents, even the poorest worker could afford to take himself and his family to the local nickelodeon or storefront theatre "Every little town that has never been able to afford and maintain an opera house," observed one journalist in 1908,"now boasts one or two 'Bijou Dreams' "By 1910 the appeal of films was so great that nearly one-third of the nation flocked to the cinema each week; ten years later, weekly attendance equaled 50 percent of the nation's population. Early films were primarily aimed at entertaining audiences, but entertainment did not always come in the form of escapist fantasies. Many of the issues that dominated Progressive-era politics were also portrayed on the screen. "Between 1900 and 1917," observes Kevin Brownlow, "literally thousands of films dealt with the most pressing problems of the day — white slavery, political corruption, gangsterism, loansharking, slum landlords, capital vs labour, racial prejudice, etc." While most of these films were produced by studios and independent cornpanies, a significant number were made by what we might call today "special interest groups". As films quickly emerged as the nation's most popular form of mass entertainment, they attracted the attention of a wide range of organizations that recognized the medium's enormous potential for disseminating propaganda to millions of viewers.

单选题Tile best title for the text may be ______.

单选题The World Health Organization (WHO) is in trouble. Its leader is accused of failing to lead, and as the organization drifts, other bodies, particularly the World Bank, are setting the global health agenda. Western governments want the WHO to set realistic targets and focus its energy on tackling major killers such as childhood diseases and tobacco. The WHO clearly needs to set priorities. Its total budget of 0.9 billion around 10p for each man, woman and child in the world-cannot solve all the worlds health problems. Yet its senior management does not seem willing to narrow the organization's focus. Instead it is trying to be all things to all people and losing dependability. Unfortunately, the argument for priority-setting is being seriously undermined by the U.S., one of the chief advocators of change. The U.S. is trying to reduce its contribution to the WHO's regular budget from a quarter of the total to a fifth. That would leave the organization 20 million short this year. On top of the substantial debts the U.S. already owes. The WHO may need priorities, but it certainly doesn't need budget cuts. Thanks to the U.S.'s failure to pay its bills, many of the poorer nations see priority-setting as merely a cover for cost cutting that would hit their health programs hard. The WHO would not serve poorer countries any worse if it sharpened its focus. It would probably serve them better. In any case, a sharper focus should not mean that less money is needed. When the U.S. demands cuts, it simply fuels disputes between the richer and poorer countries and gives the WHO's senior management more time to postpone. The American action is not confined to the WHO. It wants eventually to cut its contributions to the Food and Agriculture Organization and the International Labor Organization too. But it knows that dissatisfaction with the WHO and its leadership has made the organization vulnerable. If it wins against the WHO, the rest will lose out in their turn. America's share of the budget is already a concession. Each nation's contribution to the UN agencies is calculated according to its wealth, and by that measure the U.S. should be paying about 28 percent of the WHO budget. But over the past three decades the U.S. has gradually reduced what it pays the organization. The U.S. should not task for further cuts, until it pays its full share of money, it will hold back the organizations much needed reforms. The world needs the WHO. The World Bank may have a bigger budget, but it sees improved health as just one part of economic and social development. The WHO remains the only organization committed to health for all, regardless of wealth.

单选题What does the author mean by "that would in the end be a very bad thing"?

单选题Which of the following word is closest in meaning to the word "crippling" in paragraph 3?

单选题In the second paragraph, the author gives two examples of social problems to show that ______.

单选题 Everyone of us fives and works on a small part of the earth's surface, moves in a small circle, and of these acquaintances knows only a few intimately. Of any public event that has wide effects we see at best only a phase and an aspect. This is true that the eminent insiders, who draft treaties, make laws, and issue orders, are like those who have treaties framed on them, laws promulgated to them, orders given at them. Inevitably our opinions cover a bigger space, a longer reach of time, many things, that we can directly observe. So they have to be pieced together out of what others have reported and what we can imagine. Yet even the eyewitness does not bring back a naive picture of the scene. For experience seems to show that he himself brings something to the scene which later he takes away from it, that oftener than not what he imagines to be the account of an event is really a transfiguration of it. Few facts in consciousness seem to be merely given. Most facts in consciousness seem to be partly made. A report is the joint product of the knower and known, in which the role of the observer is always selective and usually creative. The facts we see depend on where we are placed, and the habits of our eyes.

单选题How efficient is our system of criminal trial? Does it really do the basic job we ask of it--convicting the guilty and acquitting the innocent? It is often said that the British trail system is more like a game than a serious attempt to do justice. The lawyers on each side are so engrossed in playing hard to win, challenging each other and the judge on technical points, that the object of finding out the truth is almost forgotten. All the effort is concentrated on the big day, on the dramatic cross examination of the key witnesses in front of the jury. Critics like to compare our "adversarial" system (resembling two adversaries engaged in a contest) with the continental "inquisitorial" system, under which the judge plays a more important inquiring role. In early times, in the Middle Ages, the systems of trial across Europe were similar. At that time trial by "ordeal"--especially a religious event--was the main way of testing guilt or innocence. When this way eventually abandoned the two systems parted company. On the continent church-trained legal officials took over the unction of both prosecuting and judging, while in England these were largely left to lay people, the Justice of the Peace and the jurymen who were illiterate and this meant that all the evidence had to be put to them orally. This historical accident dominates procedure even today, with all evidence being given in open court by word of mouth on the crucial day. On the other hand, in France for instance, all the evidence is written before the trial under supervision by an investigating judge. This exhaustive pretrial looks very undramatic; much of it is just a public checking of the written records already gathered. The Americans adopted the British system lock, stock and barrel and enshrined it in their constitution. But, while the basic features of our Systems are common, there are now significant differences in the way serious cases are handled. First, because the U. S. A. has virtually no contempt of court laws to prevent pretrial publicity in the newspaper and on television, American lawyers are allowed to question jurors about knowledge and beliefs. In Britain this is virtually never allowed, and a random selection of jurors who are presumed not to be prejudiced are empanelled. Secondly, there is no separate profession of barrister in the United States, and both prosecution and defense lawyers who are to present cases in court prepare themselves. They go out and visit the scene, track down and interview witnesses, and familiarize themselves personally with the background. In Britain it is the solicitor who prepares the case, and the barrister who appears in court is not even allowed to meet witness beforehand. British barristers also alternate doing both prosecution and defense work. Being kept distant from the preparation and regularly appearing for both sides, barristers are said to avoid becoming too personally involved, and can approach cases more dispassionately. American lawyers, however, often know their cases better. Reformers rightly want to learn from other countries' mistakes and successes. But what is clear is that justice systems, largely because they are the result of long historical growth, are peculiarly difficult to adapt piecemeal.

单选题In this book Henton admits that______.

单选题Why did wool to be the second woven material for clothes?