In the United States, 30 percent of the adult population has a "weight problem". To many people, the cause is obvious: they eat too much. But scientific evidence does little to support this idea. Going back to the America of the 1910s, we find that people were thinner than today, yet they ate more food. In those days people worked harder physically, walked more, used machines much less and didn't watch television. Several modern studies, moreover, have shown that fatter people do not eat more on the average than thinner people. In fact, some investigations, such as the study of 3, 545 London office workers, report that, on balance, fat people eat less than slimmer people. Studies show that slim people are more active than fat people. A study by a research group at Stanford University School of Medicine found the following interesting facts: The more the men ran, the more body fat they lost. The more they ran, the greater amount of food they ate. Thus, those who ran the most ate the most, yet lost the greatest amount of body fat.

单选题 The physical problem that many adult Americans have is that______.

【正确答案】 C

【答案解析】解析：细节判断题。答案在第一段第一句话：In the United States，30 percent of the adult population has a“weight problem”(在美国，30％的成年人都有体重问题)。因此许多美国成年人的身体问题是他们太胖了，C为正确答案。

单选题 According to the article, given 500 adult Americans, ______people will have a "weight problem".

【正确答案】 D

【答案解析】解析：逻辑推理题。答案也在第一段第一句话：30 percent of the adult population has a“weight problem”(30％的成年人都有体重问题)。因此，如果有500人的话，那么150人就会有体重问题。D为正确答案。

单选题 Is there any scientific evidence to support that eating too much is the cause of a " weight problem"?

A、 Yes, there is plenty of evidence.
B、 Of course, there is some evidence to show this is true.
C、 There is hardly any scientific evidence to support this.
D、 We don't know because the information is not given.

【正确答案】 C

【答案解析】解析：细节判断题。答案在第一段第三句话：But scientific evidence does little to support this ides(但几乎没有任何科学依据证明这一点)。C为正确答案。

单选题 In comparison with the adult American population today, the Americans of the 1910s______.

【正确答案】 A

【答案解析】解析：细节判断题。答案在第一段：Going back to the America of the 1910s，we find that people were thinner than today，yet they ate more food．In those days people worked harder physically，walked more，used machines much less and didn’t watch television(同顾十八世纪初，那时的人比现在的人瘦，然而却吃得多。那时候，他们工作比现在辛苦，走路比现在多，使用机器比现在少，也不看电视)。因此A为正确答案。

单选题 Modern scientific researches have reported to us that______.

A、 fat people eat less food and are less active
B、 fat people eat more food than slim people and are more active
C、 fat people eat more food than slim people but are less active
D、 thin people run less, but have greater increase in food intake

【正确答案】 A

【答案解析】解析：细节判断题。答案在第二段和第三段：Several modern studies have shown that fatter people do not eat more on the average than thinner people；Slim people are more active than fat people。因此胖人吃得少，活动少。A为正确答案。