C(选自2011全国四级考试) 　　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 (寡妇)and widowers 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, 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 (生理的) mechanisms. 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 ultimate social network is still being mapped out, but Christakis says: “People are interconnected, so their health is interconnected.” 　

51. William Farr’s study and other studies show that _________. 　　

A social life provides an effective cure for illness 　　B being sociable helps improve one’s quality of life 　　

C women benefit more than men from marriage 　　D marriage contributes a great deal to longevity 　

52  Linda Waite’s studies support the idea that _________. 　　

A older men should quit smoking to stay healthy 　　Bmarriage can help make up for ill health 　　

Cthe married are happier than the unmarried 　　D unmarried people are likely to suffer in later life 　

53. It can be inferred from the context that the “flip side” (Line 4, Para. 2) refers to _________. 　　

Athe disadvantages of being married 　　Bthe emotional problems arising from marriage 　　

C the responsibility of taking care of one’s family 　　D the consequence of a broken marriage 　

54. What does the author say about social networks? 　　

AThey have effects similar to those of a marriage. 　　BThey help develop people’s community spirit. 　　

CThey provide timely support for those in need. 　　DThey help relieve people of their life’s burdens. 　

55.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.