题目内容：

Many people turn to doctors or self-help books, but they ignore a powerful thing that could help them fight illness: their friends.

Researchers are only now starting to pay attention to the importance of friendship in health. A 10-year Australian study found that old People with a large circle of friends. A large 2007 study showed an increase of nearly 60 percent in the risk （危险） for obesity （肥胖） among people whose friends gained weight. And last year, Harvard researchers reported that strong social ties could improve brain health as we age.

“In general, the role of friendship in our lives isn’t well realized,” said Rebecca, a professor at the University of North Carolina. “Friendship has a bigger effect on our psychological （心理的） health than family relationships. ”

While many friendship studies are about the close relationships of women, some research shows that it can do good to men too. In a six-year study of 736 middle-aged men, having friendships reduces the risk of heart attack. Only smoking was as important a risk factor （因素） as having little social support.

Exactly why friendship has such a big effect isn’t entirely clear. While friends can send a sick person to the hospital or pick up medicine, the advantages go well beyond physical help. Friendship clearly has a big psychological effect. “People with stronger friendships feel like there is someone they can turn to,” said Karen, a doctor. “The message of these studies is that friends make your life better. ”

1.The three studies in paragraph2 show that              .

A. old people need friends the most.

B. friends can help us lose weight.

C. social ties （关系） are connected to health

D. more friends make us healthier.

2.What do underlined sentences in paragraph3 mean?

A. Friendship is more important to women than to men.

B. What people need most is a friend’s care.

C. Friendship is more important than family relationship

D. The value of friendship hasn’t been fully understood.

3.The author mentioned smoking in the text to discuss              .

A. the cause of heart attack.

B. the risk of having no friends.

C. smoking is bad for men.

D. friends’ influence on habits.