单选题 An Interesting Phenomenon

Animals seem to have the sense to eat when they are hungry and they do not eat more than their bodies need. It has been demonstrated that rats will, when given a choice over a period of time, prefer water with vitamins to water without vitamins even though there is no difference in taste or smell between the two water bottles. When a fragrant flavor was added to the vitamin-enriched fluid, the rats did seem to develop a taste for it and kept drinking it, even after the vitamins were switched to the clear water. In time, however, they broke the habit and went back to where the necessary vitamins were.
In a classic experiment, babies of 6 to 12 months old were placed in a cafeteria feeding arrangement, with a wide selection of baby food before them. They were given whatever food they pointed to or appeared interested in. We are told that at first they showed some unusual eating patterns, but that over a period of time they managed to select well-balanced diet.
So, in selecting food, rats and babies do seem to know and act on what's best for them. Apparently, there is a kind of "body wisdom", which humans soon lose. Most of us do not eat as wisely as we could. Many of our food preferences are culturally determined and influenced by long-established habits. Some people eat fox, dog and blackbirds, while we eat cows and pigs. So what people eat and how much they eat seems to be greatly influenced by what is going on around them.

单选题 In the experiment on rats, a fragrant flavor was added to the rat's drinking water to______

【正确答案】 C

【答案解析】答案依据文章第一段第二句：It has been demonstrated that rats will，when given a choice over a period of time，prefer water with vitamins to water without vitamins eventhough there is no difference in taste or smell between the two water bottles．

单选题 The expression "the habit" (para. 1, sentence 4) refers to drinking water which______

【正确答案】 D

【答案解析】因为第一段的最后谈到：“老鼠不停地喝有香味的含有维生素的液体，即使是维生素被换到了清水里面。然而，很快他就改变了这个习惯，重新开始喝有维生素的水了。”所以句子中habit实际上指前面的喝有香味的水，所以D项正确。

单选题 According to the passage, adults eating habits differ from those of babies because______

A、 adults know better than babies what kind of food are good for their health
B、 adults usually cannot resist the temptation of various delicious foods
C、 adults' eating habits are closely related to the social and cultural customs
D、 adults have more choices of food than babies in eating patterns

【正确答案】 C

【答案解析】根据文章第二段最后一句：Babies managed to select well—balanced diet．又根据文章的第三段第四句：Many of our food preferences are culturally determined and influenced bylong-established habits．由此可知成年人和婴儿的饮食习惯的不同点在于：成年人的饮食习惯和他们的社会和文化习俗有关。所以选C。

单选题 The author implied in the passage that most of us______

【正确答案】 C

【答案解析】根据上下文，我们可以知道，文章中并没有提到：“大多数人都有合理的饮食；选择有营养的食物以及喜欢有香味的食品。”因此A、B、D都是错误的。但是文章的最后一句话说：“What people eat and how much they eat seems to be greatly influenced by what is goingon around them．”因此可以断定：“我们的饮食习惯受周围环境的影响。”C是正确答案。

单选题 As far as their eating habits are concerned, babies and rats are similar in that______

【正确答案】 A

【答案解析】文章第二段最后一句话说：Babies managed to select well—balanced diet．“婴儿总能选择合理饮食。”第三段的第一句话说：So，in selecting food，rats and babies do seem toknow and act on what’s best for them．“所以，在选择食物方面，老鼠和婴儿似乎确实知道而且选择最适合自己的东西。”据此可以知道：婴儿和老鼠饮食习惯的相同点在于他们都会选择合理的饮食。只有A项最符合题意。