Many people turn to doctors or self-help books, but they forget a great 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 older people with a large circle of friends were 22 percent less likely to die during the study period than those with fewer friends. A large 2007 study showed an increase of nearly 60 percent in the danger for obesity among people whose friends gained weight. And last year, Harvard researchers reported that strong social ties(关系) 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 disease. Only smoking was as important a danger factor (因素) as having little social support.
The exact reason why friendship has such a big effect isn’t 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. "
The three studies in paragraph 2 show that _____.

A．old people need friends the most

B．friends can help us lose weight

C．social ties have something to do with health

D．having more friends makes us healthier

What do Rebecca’s words 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.

The author mentioned smoking in the text to discuss ________.

A．the cause of heart attack

B．the danger of having no friends

C．smoking is bad for men

D．Friends’ influence on habits

Which of the following has the closest meaning to the underlined word "obesity "?

A．fatness	B．unhappiness
C．excitement	D．Health