Do you have good friends？Do you sometimes feel so close to them that they are like family to you？
   It turns out that this isn't just an expression.A study by Yale University and the University of California，San Diego，has found that you and your friends have more genes in common than strangers do，the Guardian reported.
   Researchers looked at the genes of 1，932 people and compared them in pairs of unrelated friends and strangers.They found that friends have 1 percent of genes that match.
   One percent may not sound like much to the layperson（外行），but to geneticists （遺傳學(xué)家）it is a significant number，Professor Nicholas Christakis of Yale University told Discovery News.In fact，this is the same amount of genes you share with your fourth cousins，those who have the same great-great-great grandparents as you.
   So is it a coincidence（巧合）that you become friends with people who share your genes？Not at all.In fact，it is evolution that brings you together.
   People who share certain genes also share skills and have similar likes and dislikes，researchers said.In ancient times，it was critical（極其重要的）that people who were alike stayed together.For example，people who had a similar susceptibility（易感性）to the cold were more likely to help each other build a fire，giving them a better chance to survive.
   Researchers also found that among all the genes studied，those affecting sense of smell were the most similar in friends.This is probably because people who smell things in the same way are more easily drawn to similar environments.For example，people who like the smell of coffee may hang out at cafes more often and are therefore more likely to meet and become friends with each other.
   Based on their findings，the team has developed an interesting test called the "friendship score".It calculates how big the chances are that two people will be friends by studying their genes.
   So，here is a question for you：would you like to take this test and know in advance who your friends are going to be，or would you still prefer to figure it out by yourself and let time be the judge？

（1）What is the author's main purpose in writing the article？

B

B

A．To explain why friends share skills and interests.
B．To report on recent findings about making friends.
C．To analyze what influences the way people make friends.
D．To introduce an interesting test called the "friendship score".
（2）According to the researchers of the study，people

B

B

.
A．form friendships by complete coincidence
B．a(chǎn)re genetically similar to their friends，compared to strangers
C．make friends with those who share nearly 10 percent of their genes
D．may share more similar genes with their friends than with their fourth cousins
（3）With the examples of ancient people helping each other build a fire，the author intends to

C

C

.
A．show how ancient people helped each other survive
B．explain that similar interests are what lead to friendship
C．show that it is evolution that brings friends together
D．tell us why it was easier for ancient people to find friends
（4）According to the article，people with similar genes that affect their sense of smell

C

C

.
A．like to hang out at cafes more often
B．a(chǎn)re easily attracted to the smell of their friends
C．a(chǎn)re more likely to be attracted to a similar environment
D．can identify people in a crowd who can become friends