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设f(x)在(a，b)内可微，且 f(a)=f(b)=0，f’(a)＜0，f’(b)＜0，则方程f’(x)=0在(a，b)内______．
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21-25 The appeal of advertising to buying motives can have both negative and positive effects. Consumers may be convinced to buy a product of poor quality or high price because of an advertisement. For example, some advertisers have appealed to people’s desire for better fuel economy for their cars by advertising automotive products that improve gasoline mileage. Some of the products work. Others are worthless and a waste of consumers’ money. Sometimes advertising is intentionally misleading. A few years ago a brand of bread was offered to turned out that the bread was not dietetic (适合于节食的), but just regular bread. There were fewer calories because it was sliced very thin, but there were the same number of calories in every loaf. On the positive side, emotional appeals may respond to a consumer’s real concerns. Consider fire insurance. Fire insurance maybe sold by appealing to fear of loss. But fear of loss is the real reason for fire insurance. The security of knowing that property is protected by insurance makes the purchase of fire insurance a worthwhile investment for most people. If consumers consider the quality of the insurance plans as well as the message in the ads, they will benefit from the advertising. Each consumer must evaluate her or his orca situation. Are the benefits of the product important enough to justify buying it Advertising is intended to appeal to consumers, but it does not force them to buy the product. Consumers still control the final buying decision. It can be inferred from the passage that a smart consumer should______.
16-20 Two main techniques have been used for training elephants, which we may call respectively the tough and the gentle. The former method simply consists of setting an elephant to work and beating him until he does what is expected. Apart from any moral considerations this is a stupid method of training, for it produces a resentful animal who at a later stage may well turn man-killer. The gentle method requires more patience in the early stages, but produces a cheerful, good-tempered elephant who will give many years of loyal service. The first essential in elephant training is to assign to the animal a single mahout who will be entirely responsible for the job. Elephants like to have one master just as dogs do, and are capable of a considerable degree of personal affection. There are even stories of half-trained elephant calves who have refused to feed and pained to death when by some unavoidable circumstance they have been deprived of their own trainer. Such extreme cases must probably be taken with a grain of salt, but they do underline the general principle that the relationship between elephant and mahout is the key to successful training. The most economical age to capture an elephant for training is between fifteen and twenty years, for it is then almost ready to undertake heavy work and can begin to earn its keep straight away. But animals of this age do not easily become subservient to man, and a very firm hand must be employed in the early stages. The captive elephant, still roped to a tree, plunges and screams every time a man approaches, and for several days will probably refuse all food through anger and fear. Sometimes a tame elephant is tethered nearby to give the wild one confidence, and in most cases the captive gradually quietens down and begins to accept its food. The next stage is to get the elephant to the training establishment, a ticklish business which is achieved with the aid of two tame elephants roped to the captive on either side. When several elephants are being trained at one time, it is customary for the new arrival to be placed between the stalls of two captives whose training is already well advanced. It is then left completely undisturbed with plenty of food and water so that it can absorb the atmosphere of its new home and see that nothing particularly alarming is happening to its companions when it is eating normally, its own training begins. The trainer stands in front of the elephant holding a long stick with a sharp metal point. Two assistants, mounted on tame elephants, control the captive from either side, while others rub their hands over his skin to the accompaniment of a monotonous and soothing chant. This is supposed to induce pleasurable sensations in the elephant, and its effects are reinforced by the use of endearing epithets, such as ’ho! my son’, or ’ho! My father’, or ’my mother’ according to the age and sex of the captive. The elephant is not immediately susceptible to such blandishments, however, and usually lashes fiercely with its trunk in all directions. These movements are controlled by the trainer with the metal-pointed stick, and the trunk eventually becomes so sore that the elephant curls it up and seldom afterwards uses it for offensive purposes. A mature elephant is only subjected to training when______.
Directions: In this part there are four passages, each followed with five questions or unfinished statements. For each of them, there are four suggested answers. Choose the one that you think is the best answer. Mark your ANSWER SHEET by drawing with a pencil a short bar across the corresponding letter in the brackets.11-15 For an increasing number of students at American universities, Old is suddenly in. The reason is obvious: the graying of America means jobs. Coupled with the aging of the baby-boom (生育高峰) generation, a longer life span means that the nation’s elderly population is bound to expand significantly over the next 40 years. By 2040, 25 percent of all Americans will be older than 65, up from 14 percent in 1995. The change poses profound questions for government and society, of course. But it also creates career opportunities in medicine and health professions, and in law and business as well. "In addition to the doctors, we’re going to need more sociologists, biologists, urban planners and specialized lawyers," says Professor Edward Schneider of the University of Southern California’s (USC) School of Gerontology (老年学). Lawyers can specialize in "elder law", which covers everything from masts and estates to nursing-home abuse and age discrimination (歧视). Businessmen see huge opportunities in the elder market because the baby boomers, 74 million strong, are likely to be the wealthiest group of retirees in human history. "Any student who combines an expert knowledge in gerontology with, say, an MBA or law degree, will have a license to print money," one professor says. Margarite Santos is a 21-year-old senior at USC. She began college as a biology major but found she was "really bored with bacteria." So she took a class in gerontology and discovered that she liked it. She says, "I did volunteer work in retirement homes and it was very satisfying." Who can make big money in the new century according to the passage
21-25 The appeal of advertising to buying motives can have both negative and positive effects. Consumers may be convinced to buy a product of poor quality or high price because of an advertisement. For example, some advertisers have appealed to people’s desire for better fuel economy for their cars by advertising automotive products that improve gasoline mileage. Some of the products work. Others are worthless and a waste of consumers’ money. Sometimes advertising is intentionally misleading. A few years ago a brand of bread was offered to turned out that the bread was not dietetic (适合于节食的), but just regular bread. There were fewer calories because it was sliced very thin, but there were the same number of calories in every loaf. On the positive side, emotional appeals may respond to a consumer’s real concerns. Consider fire insurance. Fire insurance maybe sold by appealing to fear of loss. But fear of loss is the real reason for fire insurance. The security of knowing that property is protected by insurance makes the purchase of fire insurance a worthwhile investment for most people. If consumers consider the quality of the insurance plans as well as the message in the ads, they will benefit from the advertising. Each consumer must evaluate her or his orca situation. Are the benefits of the product important enough to justify buying it Advertising is intended to appeal to consumers, but it does not force them to buy the product. Consumers still control the final buying decision. The passage tells us that______.
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