It's not surprising, then, that millions of Americans have become obsessed (著迷) with staying slim and "in shape". The pursuit of a youthful physical appearance is not, however, the sole reason for America's obsession with diet and exercise. Recent research has shown the critical importance of diet and exercise for personal health. As in most technologically developed nations, the life-style of North Americans has changed dramatically during the course of the last century. Modern machines do all the physical labor that people were once forced to do by hand. Cars and buses transport us quickly from point to point. As a result of inactivity and disuse, people's bodies can easily become weak and vulnerable to disease. In an effort to avoid such a fate, millions of Americans are spending more of their time exercising every day.

　　1. From the passage we can infer taboo is .

　　A. a strong desire to do something strange or terrible

　　B. a crime committed on impulse

　　C. behavior considered unacceptable in society's eyes

　　D. an unfavorable impression left on other people

　　2.Based on the ideas presented in the passage we can conclude "being fat"_______.

　　A. will always remain a taboo B. is not considered a taboo by most people

　　C. has long been a taboo D. may no longer be a taboo some day

　　3.The topic of fat is_______many other taboo subjects.

　　A. the same as B. different from

　　C. more popular than D. less often talked about than

　　4.In the U. S. , thin is "in", fat is "out", this means_______.

　　A. thin is "inside", fat is "outside"

　　B. thin is "diligent", fat is "lazy"

　　C. thin is "youthful", fat is "spiritless"

　　D. thin is "fashionable", fat is "unfashionable"

　　5.The main reason the passage gives for why so many Americans are exercising regularly is_______.

　　A. their changed life-style

　　B. their eagerness to stay thin and youthful

　　C. their appreciation of the importance of exercise

　　D. the encouragement they have received from their companies

　　參考答案：

　　1. C 2. D 3. B 4. D 5. B

　　For some time past it has been widely accepted that babies and other creatures learn to do things because certain acts lead to "rewards"; and there is no reason to doubt that this is true. But it used also to be widely believed that effective rewards, at least in the early stages, had to be directly related to such basic physiological(生理的) "drives" as thirst or hunger. In other words, a baby would learn if he got food or drink or some sort of physical comfort, not otherwise.

　　It is now clear that this is not so. Babies will learn to behave in ways that produce results with no reward except the successful outcome.

　　Papousek began his studies by using milk in the normal way to "reward" the babies and so teach them to carry out some simple movements, such as turning the head to one side or the other. Then he noticed that a baby who had had enough to drink would refuse the milk but would still go on making the learned response with clear signs of pleasure. So he began to study the children's responses in situations where no milk was provided. He quickly found that children as young as four months would learn to turn their heads to right or left if the movement "switched on" a display of lights—and indeed that they were capable of learning quite complex turns to bring about this result, for instance, two left or two right, or even to make as many.as three turns to one side.

　　Papousek's light display was placed directly in front of the babies and he made the interesting observation that sometimes they would not turn back to watch the lights closely although they would " smile and bubble" when the display came on. Papousek concluded that it was not primarily the sight of the lights which pleased them, it was the success they were achieving in solving the problem, in mastering the skill, and that there exists a fundamental human urge to make sense of the world and bring it under intentional control.

　　21. According to the author, babies learn to do things which______.

　　A. are directly related to pleasure B. will meet their physical needs

　　C. will bring them a feeling of success D. will satisfy their curiosity

　　22. Papousek noticed in his studies that a baby______.

　　A. would make learned responses when it saw the milk

　　B. would carry out learned movements when it had enough to drink

　　C. would continue the simple movements without being given milk

　　D. would turn its head to right or left when it had enough to drink

　　23. In Papousek's experiment babies make learned movements of the head in order to

　　A. have the lights turned on B. be rewarded with milk

　　C. please their parents D. be praised

　　24. The babies would "smile and bubble" at the lights because______.

　　A. the lights were directly related to some basic "drives"

　　B. the sight of the lights was interesting

　　C. they need not turn back to watch the lights

　　D. they succeeded in "switching on" the lights

　　25. According to Papousek, the pleasure babies get in achieving something is a reflection of______.

　　A. a basic human desire to understand and control the world

　　B. the satisfaction of certain physiological needs

　　C. their strong desire to solve complex problems

　　D. a fundamental human urge to display their learned skills

　　參考答案：

　　21. C 22. C 23. A 24. D 25. A