Our Body and Healthy Habits單元學(xué)案
c. people of different t ages can all benefit from physical exercise
d. physical exercise is the safest treatment for losing calcium
49. active children _________ than inactive children.
a. are clever and healthier b. are clever but not stronger
c. are stronger but more foolish d. enjoy walking more
50. from the passage, we know that __________.
a. mice need to eat more and exercise more
b children need more exercise than other people
c. old people like to take medicine to treat their illness
d. middle aged people are easy to get fat
51. the bones of old people are easy to break because ___________.
a. there is less calcium in their bones than in those of other people
b. they are easy to become ill
c. they eat less than other people
d. they have less exercise than other people
e
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 proved 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(流體) , the rats did seem to develop a taste for it and kept drinking it. after the vitamins were changed to the clear water in time, however, they broke the habit and back to where the necessary vitamins were.
in a classic experiment, babies of 6 to 12 months old were placed in a cafeteria (自助餐廳) feeding arrangement, with a wide choice 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 period of
time they managed to choose a well balanced diet.
so in choosing food, rats and babies do seem to know and act on what’s best for them.
obviously, 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 foxes, dogs and blackbirds, while we eat cows and pigs.