题目内容：

Being sociable looks like a good way to add years to your life. Relationships with family, friends, neighbours, even pets, will all do the trick, but the biggest longevity(长寿) boost seems to come from marriage or an equivalent relationship. The effect was first noted in 1858 by William Farr, who wrote that widows and widowers(鳏夫) were at a much higher risk of dying than their married peers. Studies since then suggest that marriage could add as much as seven years to a man’s life and two to a woman’s. The effect holds for all causes of death, whether illness, accident or self-harm.

Even if the odds are stacked against you (the conditions are not favourable), marriage can more than compensate. Linda Waite of the University of Chicago has found that a married older man with heart disease can expect to live nearly four years longer than an unmarried man with a healthy heart. Likewise, a married man who smokes more than a pack a day is likely to live as long as a divorced man who doesn’t smoke. There’s a flip side, however, as partners are more likely to become ill or die in the couple of years following their spouse’s death, and caring for a spouse with mental disorder can leave you with some of the same severe problems. Even so, the odds favour marriage. In a 30-year study of more than 10,000 people, Nicholas Christakis of Harvard Medical School describes how all kinds of social networks have similar effects.

So how does it work? The effects are complex, affected by socio-economic factors, health-service provision, emotional support and other more physiological mechanisms (机制). For example, social contact can boost development of the brain and immune system, leading to better health and less chance of depression later in life. People in supportive relationships may handle stress better. Then there are the psychological benefits of a supportive partner.

A life partner, children and good friends are all recommended if you aim to live to 100. The best social network is still being mapped out, but Christakis says: “People are interconnected, so their health is interconnected.”

1.Which one of the following is TRUE according to the text?

A. The married men live seven years longer than the unmarried.

B. Marriage can help make up for ill health.

C. The unmarried are more likely to have heart disease than the married old men.

D. Unmarried people are likely to suffer in later life.

2.According to the context, what does the “flip side” in Paragraph 2 refer to?

A. The disadvantages of being married.

B. The emotional problems arising from marriage.

C. The responsibility of taking care of one’s family.

D. The consequence of a broken marriage.

3.What does the author say about social networks?

A. They contribute a great deal to longevity.

B. They help develop people’s community spirit.

C. They provide timely support for those in need.

D. They help relieve people of their life’s burden.

4.What can be inferred from the last paragraph?

A. It’s important that we develop a social network when young.

B. To stay healthy, one should have a proper social network.

C. Getting a divorce means risking a reduced life span.

D. We should share our social networks with each other.