题目内容：

    Keeping a busy social life among lots of friends may keep people thinner than spending several hours in a gym, according to scientists. Scientists believe social activities can release a brain chemical that changes white fat into brown fat. Brown fat burns calories (卡路里). To produce heat, while white fat keeps calories and make us fatter.

Changing white fat into brown fat is very difficult, generally requiring long-term exposure to cold conditions or making part of the body’s nervous (神经的) system active. However, scientists from Ohio State University think that having a busy social life is an even better way of carrying out this change.

Tests on mice showed that those lived in large communities and had more space and toys lost half of their stomach weight in four weeks, even if they ate more than those in boring, lonely environments. Researchers said that social excitement helps lose weight.

However, social activities make some people worried. Study writer Dr Matthew During said, “I’m still amazed at the degree of losing fat that happens. We often think of stress (压力) as a negative thing, but some kinds of stress can be good for your health.”

Explaining how new technology had reduced the chance for people to communicate face to face, he added, “It’s not just because of being short of exercise and high calorie foods, but an increasing lack of social activities. Loneliness is a deep cause of cancer and death, it’s just as dangerous as smoking. Social activities are very important.

根据短文内容选择最佳答案。

1.The underlined word “exposure” means________in Chinese.

A.勘探 B.适应 C.暴露

2.When people take social activities, a brain chemical can change white fat into________.

A.brown fat B.calories C.energy

3.According to the tests on mice, ________.

A.Taking more social activities will work for losing weight, even if you eat more.

B.Mice living in boring and lonely environments will gain weight although they eat less.

C.The results from test on mice aren’t fit for humans.

4.Which of the following is TRUE according to the passage?

A.Brown fat keeps calories and make people fatter while white fat burns calories to produce heat.

B.To change white fat into brown fat, long-term exposure to cold conditions is required.

C.Unlike smoking, loneliness can cause cancer and even death.

5.The best title for the passage can be ________.

A.Social Activities Help Lose Weight

B.Brown Fat and White Fat

C.Loneliness Is Dangerous