1 . Keeping a busy social life among lots of friends may keep people thinner than spending hours doing some exercises, according to scientists. They say that socialising and meeting with friends help increase levels of brown fat in the body which burns calories(卡路里)to produce heat.

     Living in an exciting social environment was found to reduce fat in mice's belly by half over four weeks, even if they ate more. US researchers say that social excitement aids weight loss by turning white fat into brown. White fat stores calories and makes us fatter, while brown burns energy to produce heat. Turning white fat into brown is extremely difficult，normally requiring long- term stay in cold conditions or exciting part of the body's nervous system.

However, scientists from Ohio State University now think that having a busy social life is an even more effective way of changing white fat into brown. The team came up with their theory by studying the effects of various living environments on mice. Those, who lived alongside a greater number of mice, had more space and toys to excite themselves and then lost far more weight over the course of the study than their “couch potato" fellows.

   Study author, Dr Matthew During, whose team's findings appear in the journal Cell Metabolism, said, "I'm still amazed at the degree of fat loss that occurs." Explaining how new technology had threatened face-to-face socialising, he added, "It's not just a sedentary(久坐 的)lifestyle and high calorie foods, but an increasing lack of social activities." Co-author Dr Lei Cao said，"Loneliness is a potential factor for cancer and death; it's equal to cigarette smoking to a certain extent. Social activities are very vital.，，
1. What information can we get from the first two paragraphs?

A．Brown fat stores calories and makes us fatter.

B．It doesn't take long to turn white fat into brown.

C．Social excitement helps gain more weight.

D．Brown fat can burn energy to produce heat.

2. Which of the following statement does the text support?

A．Levels of brown fat can be increased by socialising.

B．The mice lacking social life lose more weight.

C．The research findings haven't been published so far.

D．Dr Matthew During wasn't convinced of the result.

3. We can conclude from the text that _______.

A．the fat in mice's belly was reduced because of the relaxing environment

B．a sedentary lifestyle and high calories foods influence people's social life

C．surfing the Internet may influence people's face-to-face communication

D．cancer and death are mainly caused for lack of social life

4. What’s the main idea of the text?

A．Brown fat is beneficial to people's health.

B．Socialising is unnecessarily important in people's daily life.

C．White fat can be changed into brown fat.

D．Socialising contributes to people's losing weight.