题目内容：

How to Make Friends, According to Science

Friendship is one of life’s most important features, and one too often taken for granted.

The human desire for companionship may feel boundless, but research suggests that our social capital is finite—we can only handle a certain number of relationships at one time. Social scientists have used some creative approaches to measure the size of people’s social networks; these have returned estimates ranging from about 250 to about 5,500 people. Looking more specifically at friendship, a study using the exchange of Christmas cards to test closeness put the average person’s friend group at about 121 people. However vast our networks may be, our inner circle tends to be much smaller. The average American trusts only 10 to 20 people. Moreover, that number may be shrinking: From 1998 to 2017, the average number of trusted friends decreased from three to two. This is both sad and of important consequence, because people who have strong social relationships tend to live longer than those who don’t.

So what should you do if your social life is lacking? Here the research is instructive. To begin with, don’t refuse to consider the humble acquaintance（交情）. Even interacting with people with whom one has weak social ties has a meaningful influence on well-being. Beyond that, building deeper friendships may be largely a matter of putting in time. A recent study out of the University of Kansas found that it takes about 50 hours of socializing to go from acquaintance to casual friend, an additional 40 hours to become a “real” friend, and a total of 200 hours to become a close friend.

If that sounds like too much effort, renewing inactive social ties can be especially rewarding. Reconnected friends can quickly recapture the trust they previously built, while offering each other a dash of novelty（新奇）drawn from whatever they’ve been up to in the meantime. And if all else fails, you could start randomly to tell secrets to people you don’t know that well. Self-disclosure makes us more likable, and as a bonus, we are more likely to favor those to whom we have revealed our soul.

Longing for closeness and connection is common and everywhere, which suggests that most of us are stumbling（跌跌撞撞）through the world, expecting companionship that could be easily provided by the lonesome stumblers all around us. So set aside this article, turn to someone nearby, and try to make a friend.

1.From Paragraph 2, we can know that             .

A. a strong social relationship can guarantee a long life

B. real friendships are based on the exchange of presents

C. people’s inner circle is decreasing despite large social networks

D. people’s social networks depend on their desire for companionship

2.What does the author suggest to improve one’s social life?

A. Sharing secrets with close friends.

B. Choosing likable people as friends.

C. Avoiding the humble acquaintance.

D. Spending time for deeper friendships.

3.What is the passage mainly about?

A. The tips on how to develop friendship.

B. The reasons for seeking companionship.

C. The benefits brought by a good social life.

D. The relationship between friendship and happiness.

4.The author helps readers better understand his idea mainly by             .

A. using research results

B. making comparisons

C. giving some examples

D. telling personal stories