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问题 计算题

用公式法解下列方程：

（1）x2-6x+3=0

（2）5x2-8x+2=0

（3）2x（x+4）=1

答案

单项选择题

设函数f(x)在x=0可导且f(0)=0，f’(0)=b，若在x=0连续，那么常数A=（）。

A．a+b

B．-a-b

C．a-b

D．b-a
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填空题

Part 4


Questions 26-45


·Read the following passage and choose the best word for each space.
Money spent on advertising is money spent as well as any (26) know of. It serves directly to assist a rapid of goods at reasonable prices, (27) establishing a firm home market and so making it possible to provide (28) export at competitive prices. By drawing attention to new ideas it helps enormously to raise standards of living. By helping to increase demand it (29) an increasing need for labor, and is therefore an effective way to fight unemployment. It lowers the costs of many services: (30) advertisements your daily newspaper would cost four times as much, the price of your television license would need to be doubled, and travel by bus or tube would cost 20 percent more.
And perhaps most important of all, advertising provides a guarantee of reasonable value in the products and services you buy (31) the fact that twenty-seven Acts of Parliament govern the terms of advertising, no regular advertiser dare promote a product that fails to live (32) the promise of his advertisements. He might fool some people for a little (33) through misleading advertising. He will not do so for long, for mercifully the public has the good (34) not to buy the inferior article more than once. If you see an article (35) advertised, it is the surest proof. I know that the article does what is (36) for it, and that it represents good value.
Advertising does more for the (37) benefit of the community than any other force I can think of.
There is one more point I feel I ought to (38) on. Recently I heard a well-known television personality (39) that he was against advertising because it persuades rather than informs. He was drawing (40) fine distinctions. Of course advertising (41) to persuade.
If its message were (42) merely to information—and that in itself (43) difficult if not impossible to achieve, (44) even a detail such as the choice of the color of a shirt is subtly persuasive — advertising would be so boring (45) no one would pay any attention. But perhaps that is what the well-known television personality wants.

A．is

B．will be

C．would be

D．was
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