阅读理解. When one person gains weight , their close friends oftenfollow. Researchers have just offered evidence in a study that says obesity (肥胖) appears to spread through social ties. But the findings might also offer hope. If friends help make obesity acceptable , then they might also be influential in losing the fat .The researchers note that support groups are already an effective tool in dealing with other socially influenced problems , likealcoholism (酗酒 ) . The findings appeared in the New EngLand Journal of Medicine. The researchers used information collected from 12, 000 people. It was collected between 1972 and 2003 as part of the Framingham Heart Study. The information was highly detailed. There was even contact information(联络信息 ) for close friends of the people in the study. The researchers examined more than 40 , 000 social ties. They found a person's chances of becoming severely overweight increased by 50% if a friend had become obese. A sister or brother of a person who became obese had a 40% increased chance of becoming obese. The risk for a wife or husband was a little less than that. Nicholas Christakis of Harvard Medical School was a lead researcher in the study. He says there is a direct causal relationship (因果关系) betweena persongetting fatand being followed in weight gain by a friend. The study found that the sex of the friends was also an influence. In same-sex friendship, a person had a 71%increased risk of becoming obese. Men had a 44% increased risk of becoming obese after weight gainin a brother. In sisters ,it was 67% . The researchers also considered the effect of where people lived in relation to each other. James Fowler of the University of California,was the other lead expert. He says a friend who lives a few hundred kilometers away has as much influence as one in the same neighhorhood. He says the study demonstrates the need to consider that a major part of people's health is tied to their social connections. Both researchers say their research shows that obesity is not just a private medical issue , but a public health problem. 1. What does the underlined sentence in Paragraph 2 mean?______ A. Obesity is a negative influence on close friends. B. Friends might also play a part in losing weight. C. One might have positive influence on one's friend. D. Friendship may have little to do with one's health. 2. Which of the following statements would Nicholas Christakis agree to?______ A. If one gains weight, one's friends are likely to get fat. B. Social problems like alcoholism are easy to deal with. C. Friends usually don't follow each other to lose weight. D. One might influence others on their social behavior. 3. The increased risk of gaining weight by an obese sister is _______. A. 50% B. 40% C. 67% D. 71% 4. James Fowler seems to believe that________. A. a friend who lives nearby affects us most B. one's health has nothing to do with friends C. social connections have effects on one's life D. a friend living faraway has the same influence as one's neighbor 5. The author makes his point clear in the text________. A. a major part of people's health is based on their genes B. friends living closer have greater influence on one's health C. social relationship is closely connected with people's health D. people's physical condition is subject to social connections