Animals seem to have the sense to eat when they are hungry and they do not eat more than t

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 shown that rats will, when given a choice over a period of time, prefer water with vitamins(维生素) to water without vitamins, even though there is no difference in taste or smell between the two water bottles. When a sweet smell was added to the vitamins-enriched water, the rats did seem to develop a taste for it and kept drinking it, even after the vitamins were changed to the clear water. In time(最后), however, they broke the habit and went back to where the necessary vitamins were.
In experiments, babies of 6 to 12 months old were placed in a room with many choices 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 habits, but over a period of time they managed to choose a well-balanced diet.
So in choosing food, rats and babies do seem to know what's best for them. Clearly, 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 old habits. Some people eat foxes, dogs and blackbirds, while we eat cows and pigs. So what people eat and how much they eat seem to be greatly influenced by what is going around them.
【小题1】 In the experiment on rats, a sweet smell was added to the rats’ drinking water to      .   A．encourage rats to drink vitamins-enriched waterB．test whether rats know which drink is good for themC．find out rats’ preference in flavor(口味)D．show the vitamins are tasteless【小题2】Talking about eating habits, babies and rats are just like each other because      .A．both have the wisdom to choose a balanced dietB．both prefer flavored food and drinkC．both have the same eating habitsD．both develop a taste for the same kinds of food【小题3】In the experiment mentioned in the second paragraph, babies were      .A．given many choices of drinksB．placed and fed in a hospitalC．given all kinds of baby foodD．trained to select a balanced diet【小题4】Grown-up people’s eating habits differ from those of babies because      .A．they know better than babies what kinds of food are good for their healthB．they usually cannot say no to all kinds of delicious foodsC．their eating habits have much to do with the social and cultural customs D．they have more choices of food than babies in eating patternsB