问题 单项选择题

某一地区发生小儿麻痹症疫情,现场调查12~23月龄儿童的小麻糖丸覆盖率,结果如下:人群中儿童全程免疫覆盖率为60%,人群中儿童非免疫接种的比例为20%,病例中儿童全程免疫覆盖率为10%,病例中非免疫接种的比例为70%,则疫苗保护率为()

A.43%

B.60%

C.5%

D.86%

E.95%

答案

参考答案:E

阅读理解

阅读理解。

     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 to water without vitamins even there is no difference in taste or smell between the two water

bottles. When a fragrant flavor (香味) was added to the vitamin-enriched water, 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 they pointed to or appeared

interested in. We are told that at first they showed some unusual eating patterns (方式), but 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 foxes, dogs 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.

1. As far as their eating habits are concerned, babies and rats are similar in that both _____.

A. have the natural abilities to choose a balanced diet

B. develop a taste for the same kinds of flavors

C. have the same eating patterns

D. prefer flavored food and drink

2. In the experiment on rats, a fragrant flavor was added to the water to _____.

A. prove that vitamins are tasteless

B. find out rats preference in flavor

C. encourage rats to drink vitamin-enriched water

D. test whether rats know which drink is good for them

3. According to the passage, adults eating habits differ from those of babies because _____.

A. adults have more choices of food than babies in eating patterns

B. adults usually cannot resist the temptation of various delicious food

C. adults' eating habits are closely related to the social and culture customs

D. adults know better than babies what kinds of food are good for their health

选择题