填空题(After having studied) (so hard) for more than two months, he (felt confidently) of (success). A. After having studied B. so hard C. felt confidently D. success

填空题Between 5,000 million and 4,000 million years ago the Earth was formed, By 3,000 million years ago life had arisen and we have fossils of microscopic bacteria-like creatures to prove it. (66) Nobody knows what happened, but theorists agree that the key was the spontaneous arising of self-replicating entities, i. e. something equivalent to "genes" in the general sense. The atmosphere of the early Earth probably contained gases still abundant today on other planets in the solar system. Chemists have experimentally reconstructed these ancient conditions in the laboratory. If plausible gases are mixed in a flask with water, and energy is added by an electric discharge (simulated lightning), organic sub-stances are spontaneously synthesized. These include the building blocks of RNA and DNA. It seems probable that something like this happened on the early Earth. Consequently, the sea would have become a "soup" of prebiological organic compounds. (67) Today the most famous self-replicating molecule is DNA (deoxyribonucleic acid), but it is widely thought that DNA itself could not have been present at the origin of life because its replication is too dependent on support from specialized machinery, which could not have been available before evolution itself began. DNA has been described as a" high-tech" molecule which probably arose some time after the origin of life itself. Perhaps the related molecule RNA, which still plays various vital roles in living cells, was the original self-replicating molecule. Or perhaps the primordial replicator was a different kind of molecule altogether. (68) Variants that were particularly good at replication would automatically have come to predominate in the primeval soup. Varieties that did not replicate, or that did so inaccurately, would have become relatively less numerous. This led to ever-increasing efficiency among replicating molecules. As the competition between replicating molecules warmed up, success must have gone to the ones: hat happened to hit upon special tricks or devices for their own self-preservation and their own rapid replication. The rest of evolution may be regarded as a continuation of the natural selection of replicator molecules, now called genes, by virtue of their capacity to build for themselves efficient devices (cells and multicellular bodies) for their own preservation and reproduction. (69) Fossils were not laid down on more than a small scale until the Cambrian era, nearly 600 million years ago. The first vertebrates may date back 530 million years, according to fossil evidence--primitive, lawless fishes with fins, gills, and fish-like muscle patterns--found in China in 1999. Vertebrates appear abundantly in fossil beds between 300 and 400 million years ago. (70) Mammals and, later, birds, arose from two different branches of reptiles. The rapid divergence of mammals into the rich variety of types that we see today, from opossums to elephants, from anteaters to monkeys, seems to have been unleashed into the vacuum left by the catastrophic extinction of the dinosaurs, 65 million years ago.A. Among vertebrates, the land was first colonized by lobe-finned and lung-bearing fish about 250 million years ago, then by amphibians and, in more thoroughgoing fashion, by various kinds of animals that we loosely lump together as reptiles.B. Once self-replicating molecules had been formed by chance, something like Darwinian natural selection could have begun: variation would have come into the population because of random errors in copying.C. It is not enough, of course, that organic molecules appeared in the primeval soup. The crucial step, as noted above, was the origin of self-replicating molecules, molecules capable of copying themselves.D. Although we naturally emphasize the evolution of our own kind--the vertebrates, the mammals, and the primates--these constitute only a small branch of the great tree of life.E. Three thousand million years is a long time, and it seems to have been long enough to have produced such astonishingly complex contrivances as the vertebrate body and the insect body.F. Some time between these two dates--independent molecular evidence suggests about 4,000 million years ago--that mysterious event, the origin of life, must have occurre

填空题 {{U}}Each day, 50, 000 shiny, fire-engine-red Gala apples work the way through a sprawling factory in Swedesboro, N. J.{{/U}} (87) {{U}}Inside, 26 machines wash them, core them, peel them, seed them, slice them, chill them.{{/U}} At the end of the line, (88) {{U}}they are dunked in a solution of calcium ascorbate and now deposited into little green bags featuring a jogging Ronald McDonald.{{/U}} From there, (89) {{U}}the bags make their way in refrigerated trucks to refrigerated containers in distribution centers, then to thousand of McDonald's restaurants up and down the Eastern Seaboard.{{/U}} (90) {{U}}No more than 14 days before leaving the plant, the fruit will take the place of French fries in some child's Happy Meal{{/U}}. The apple slices, called Apple Dippers, are a symbol of how McDonald's is trying to offer healthier food to its customers (91) {{U}}and to answer the many critics who contend that most of its menu is poor nutritional quality.{{/U}} (92) {{U}}McDonald's has also not introduced a variety of "premium" salads, which will soon be joined by a salad of grapes, walnuts--and, of course, apples.{{/U}} (93) {{U}}Yet it still remains to be seen these new offerings will assuage the concerns of public health officials and other critics{{/U}} of McDonald's highly processed fat and calorieladen sandwiches, drinks and fries. (94) {{U}}So far, however, they have not--at least not have entirely.{{/U}} But this much is already clear: just as its staple meals of burger and fries have made McDonald's the largest single buyer of beef and potatoes in the country, (95) {{U}}its new focus on fresh fruits and vegetables is making the company a minor player on $ 80 billion American produce industry.{{/U}}

填空题In Chicago, a computerized system has been developed that controls traffic in the city"s seven on expressways now, one man—a controller—can follow the movement of Chicago"s traffic as looking at a set of lights. 1 The system uses electronic sensors that is built into each 2 expressway, half a mile each apart. Several times 3 a second, the computer receives information for each 4 sensor and translates it into green, yellow, or red lights in a map in the control room. 5 A green light means traffic is moving forty-five to sixty miles an hour, yellow means heavy traffic-cars stopping still or moving less than thirty miles an hour. 6 "See that red light near Austin Avenue?" the controller asked a visitor, "That"s a repair truck fix the 7 road, and the traffic has to go near it." 8 At the Roosevelt road entrance to the expressway, the light kept changing from green to red and back to green also. "A lot of trucks get on the expressway 9 there." the controller explained, "They can"t speed forward as fast as cars." 10 The sensors show immediately where an accident or a stopped car is blocking traffic, and a truck is sent by radio to clear the road. The system has lowered accidents by 18 percent. There are now 1.4 deaths on Chicago"s expressways for each one hundred million miles traveled, while nationally there are 2.6.

填空题A series of experiments were carried out by B. Latane and J. Darley. They studied the reaction of bystanders to emergency situations. Since car accidents, drownings, fires, attempted suicide, and the like arouse feelings of fear and morbid interest, these situations attract large numbers of people who stand fascinated watching the event. Yet, it is a strange aspect of crowd behavior that often nothing is done to help the victim. (71) Journalists writing of such events often claimed that this kind of behavior is due to apathy, indifference, or lack of concern. To account for any bystander's decision to act or not to act, the authors of the paper ask us to consider the basic characteristics of an emergency situation. Emergencies involve threat or harm certainly to the victim and possibly to those who try to help him (or her). The events are highly unusual, different from the normal course of life and also from each other. (72) Since little secondhand wisdom on the subject is available, it is difficult to cope with a genuine emergency by relying on such worn-out clichés as "Women and children first" or "Send for the police." The authors tell us that it is perhaps surprising that anyone should intervene at all. (73) Latane and Darley were interested, therefore, in trying to isolate the factors that make a person decide to act. It seemed to them that an individual is more likely to take action when he or she is alone than when part of a group. Latane and Darley theorized that when only one bystander is present, he or-she must judge the situation alone and decide whether to act or not. Only the bystander is responsible for the decision. The presence of other people, however, affects a person's assessment of the costs and rewards of intervention. (74) The results of the experiments confirmed the theory. They showed that the immediate social environment is more important in determining a person's reaction to an emergency than are such vague cultural or personality concepts as "apathy" or "indifference." They also help to explain why the failure to intervene seems more common in large cities than in rural areas. In large cities, the members of the crowd that gathers do not take action because they do not feel individually responsible. They may be concerned, but they watch one another, uncertain of how to act, knowing that responsibility is shared. In rural areas, however, witnesses to an emergency are likely to be alone. They must take all the responsibility for their actions and are not made embarrassed or unsure by the presence of others. (75) A. Thus, people have little experience with handling them.B. They are, therefore, more likely to come to the aid of the victim.C. The police asked some of the bystanders about the accident.D. The investigators had noted this phenomenon and asked themselves why in most cases bystanders do not act.E. This is because when there is a group, responsibility is diffused over all the members.F. But people do sometimes interven

填空题 The author is mainly talking about ______. 11 Paper cutting and model making require great ______ and attention to detail. 12 Hobby will make your spare time interesting and ______. 13 Many people prefer ______ hobbies—sailing, cycling, and so on. 14 According to the author, the hobby will give you much ______. 15

填空题No single element has tantalized and tormented the human imagination more than the shimmering metal known by the chemical symbol Au. For thousands of years the desire to possess gold has driven people to extremes, fueling wars and conquests, girding empires and currencies, leveling mountains and forests. (71) Yet its chief virtues—its unusual density and malleability along with its imperishable shine—have made it one of the world's most coveted commodities, a transcendent symbol of beauty, wealth, and immortality. From pharaohs (who insisted on being buried in what they called the "flesh of the golds") to the forty-niners (whose mad rush for the mother lode built the American West) to the financiers (who, following Sir Isaac Newton's advice, made it the bedrock of the global economy); (72) Humankind's feverish attachment to gold shouldn't have survived the modern world. Few cultures still believe that gold can give eternal life, and every country in the world—the United States was last, in 1971—has done away with the gold standard. (73) The price of gold, which stood at $ 271 an ounce on September 10, 2001, hit $1,023in March 2008, and it may surpass that threshold again. Aside from extravagance, gold is still continuing to play its role as a safe haven in perilous times. (74) In 2007 demand outstripped mine production by 59 percent. "Gold has always had this kind of magic," says Peter L. Bernstein, author of The Power of Gold. "But it's never been clear if we have gold or gold has us. " While investors flock to new gold-backed funds, jewelry still accounts for two-thirds of the demand, generating a record $53.5 billion in worldwide sales in 2007. (75) However, such concerns don't ruffle the biggest consumer nations, namely India, where a gold obsession is woven into the culture, and China, which leaped past the U.S. in 2007 to become the world's second largest buyer of gold jewelry. A. But gold's luster (光泽) not only endures; fueled by global uncertainty, it grows stronger. B. Gold is not vital to human existence; it has, in fact, relatively few practical uses. C. In the U. S. an activist-driven "No Dirty Gold" campaign has persuaded many top jewelry retailers to stop selling gold from mines that cause severe social or environmental damage. D. Nearly every society through the ages has invested gold with an almost mythological power. E. For all of its allure, gold's human and environmental toll has never been so steep. Part of the challenge, as well as the fascination, is that there is so little of it. F. Gold's recent surge, sparked in part by the terrorist attack on 9/11, has been amplified by the slide of the U. S. dollar and jitters over a looming global recession.

填空题Further education is officially (described) as the post-secondary stage of education, (comprised) all vocational and nonvocational (provision made) for young people who have left school, (or for adults).A. describedB. comprisedC. provision madeD. or for adults

填空题Satellite technology (means) (that people) can watch the same TV programs in (other) parts of the world (like) in America. A. means B. that people C. other D. like in

填空题(In) the same way that (news services) have changed (since) the invention of television. So(does) entertainment. A. In B. news services C. since D. does

填空题The committee (for) local development (asked) that the new highway (is built) (alongside) the railroad. A. for B. asked C. is built D. alongside

填空题School counselors (are convinced) that it will be obligatory that everyone (must have) (some computer training) in order to (enter) the job market. A. are convinced B. must have C. some computer training D. enter

填空题To control {{U}}quality{{/U}} and {{U}}making{{/U}} decisions {{U}}about{{/U}} production are among the many responsibilities of an {{U}}industrial{{/U}} engineer. A. quality B. making C. about D. industrial

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