Are you a social butterfly, or do you prefer being at the edge of a group of friends? Either way, your genes and evolution may play a major  1  , US researchers reported on Monday.

While it may come as no surprise that genes may help explain  2  some people have many friends and others have  3  , the researchers said, their findings go just a little farther than that.

"Some of the things we find are  4    uncommon," said Nicholas Christakis of Harvard University in Massachusetts, who helped   5  the study.

"We find that how interconnected your friends are   6   on your genes. Some people have four friends who know each other and some people have four friends who don't  7  each other.  8     Dick and Harry know each other depends on Tom's  9    ," Christakis said in a telephone interview.

Christakis and colleague James Fowler of the University of California San Diego are  10     known for their studies that show obesity, smoking and happiness spread in networks.

For this study, they and Christopher Dawes of UCSD used national data that   11   more than 1,000 identical(同卵的) and fraternal（异卵的） twins’ genes. Because  12  share an environment, these studies are good for showing the impact that genes have  13  various things, because identical twins  14  all their genes while fraternal twins share just half.

"We found there appears to be a genetic tendency to introduce your friends  15  each other," Christakis said.

There could be good, evolutionary reasons  16  this. People in the middle of a social network could be secret to useful gossip,  17   the location of food or good investment choices.

But they would also be at risk of catching effects from all sides -- in which case the advantage would  18   more cautious social behavior, they wrote in the Proceedings of the National Academy of Sciences.

"It may be that natural selection is  19  not just things like whether or not we can resist the common cold, but also who it is that we are going to come into  20   with," Fowler said in a statement.

(    ) 1. A. role                 B. rule           C. roll                  D. pole

(    ) 2. A. where              B. why          C. when                D. how

(    ) 3. A. a few                      B. several      C. few                  D. some

(    ) 4. A. generally          B. mainly      C. mostly              D. frankly

(    ) 5. A. conduct            B. introduce   C. conflict            D. instruct

(    ) 6. A. depends            B. bases         C. take                 D. put

(    ) 7. A. see                   B. inspect      C. learn                D. know

(    ) 8. A. When               B. Where       C. What                D. Whether

(    ) 9. A. genes                      B. brains        C. appearances      D. figures

(    ) 10. A. much             B. best           C. very                 D. least

(    ) 11. A. recorded         B. illustrated C. described          D. compared

(    ) 12. A. brothers          B. sisters        C. twins                D. cousins

(    ) 13. A. with                      B. on             C. for                   D. to

(    ) 14. A. share              B. have          C. own                 D. show

(    ) 15. A. into                B. to             C. in                    D. from

(    ) 16. A. for                 B. with          C. to                    D. at

(    ) 17. A. in addition to B. due to       C. as for                      D. such as

(    ) 18. A. lie on             B. bring in     C. lie in                D. send in

(    ) 19. A. acting on               B. putting on C. relying on         D. sending on

(    ) 20. A. contract          B. face          C. join                  D. contact

Ants have a reputation for strength,organization and teamwork.But researchers have now discovered that a key secret to the success of ants is their ability to identify the importance of age in the work place.

A study of Gentral American leaf-cutter ants has shown that the younger and stronger members are give the toughest job of cutting therough the leaves they harvest.Their sharp youn teeth do this job effectively,but as they get older their teeth become relatively worn and blunt.

But rather than being retired or abandoned by the group,the ageing ants are given a new role more suyted to their physical abilities.They become carriers and teansport the leaves back to the kingdom where they are harvested for food.

The findings by researchers from the University of Oregon and the Oregong State University support previous research showin the survival of a leaf-cutter kingdom depends on the efficiency(效率）of is workers.

“Cuting leaves is hard work,”said Dr.Robert Schofield,who led the research team.“Much of the cutting is done with a V-shaped blade(刀片）between teeth on their jaws.This blade starts out as sharp as the sharpest razor blade that humans have developed.”But over rime the teeth become blunter and the cutting job slows down.The team estimated that,because of this age-related wear,a colony(蚁群)spent twice the energy cutting leaves than it would if all the ants had sharp blades.Its findings support the idea that wear and break can be significant problems for insects as well as largre animals.

Like humans,leaf-cuttre ant recognize that older members of the group can still make a worhwhile contribution to society.“This study shows an advantage of social living that we are familiar with,”said Dr.Schofield.

1.The younger and stronger ants do the toughest job because      .

2.The undrelined word“blunt”in the second paragraph can be replaced by      .

3.What happens to the ants when they become old?

4.It can be learned from the passage that       .

5.What can be the best title for the passage?

The stereotype (固有观念) of computer scientists as nerds who stay up all night coding and have no social life may be driving women away from the field, according to a new study published this month. This stereotype can be brought to mind based only on the appearance of the environment in a classroom or an office.

“When people think of computer science the image that immediately pops into many of their minds is about the computer geek(怪人) surrounded by such things as computer games, science fiction and junk food，” said Sapna Cheryan, a university of Washington assistant professor of psychology and the study's lead author. “That stereotype doesn't appeal to many women who don't like the portrait of masculinity(男性化)．”

Cheryan set up four experiments involving more than 250 female and male students who were not studying computer science to look at possible reasons why the proportion of women in the field is dropping while the proportion of women in such disciplines as biology, mathematics and chemistry is increasing.

In the first experiment, students entered a small classroom that either contained objects stereotypically associated with computer science such as Star Trek posters, video game boxes and Coke cans, or non－stereotypical items such as nature posters, art, a dictionary and coffee cups. The students were told to ignore these objects because the room was being shared with another class. After spending several moments in the classroom, the students filled out questionnaires(调查问卷) that asked about their attitude toward computer science.

Women exposed to the stereotypical setup expressed less interest in computer science than those who saw the non－stereotypical objects. Men placed in the same situations did not show a similar drop in interest in computer science. Cheryan said this study suggests that a student's choice of classes or a major can be influenced by the appearance of classrooms, halls and offices.

6. The underlined word “nerds” in Paragraph 1 probably refers to “________”．

A. dull persons  B. active persons

C. intelligent persons  D. funny persons

7. Women are less likely to choose computer science because ________.

A. it is too difficult for them

B. they have wrong understanding of it

C. the lifestyle of computer scientists turns them away

D. they don't like the social life of computer scientists

8. A woman would probably lose interest in computer science when she sees a ________.

A. Star Trek poster               B. nature poster

C. dictionary                   D. coffee cup

9. What can influence a woman's choice of classes, according to the passage?

A. The contents of computer science.

B. The space in the classroom.

C. The number of students in the classroom.

D. The classroom environment.

10. According to the experiment, women are more likely to choose computer science if ________.

A. it is made more lively and interesting

B. they are exposed to the stereotypical setup

C. they see the non－stereotypical objects in the classroom

D. they are allowed to learn it without men

第二卷（共35分）

第四部分：写作（共两节，满分35分）

任务型读写（共10小题；每空1分，满分10分）

阅读下列短文，根据所读内容在文章后的表格中填入恰当的单词。注意：表格中的每个空格只填1个单词

Can the thought of loved ones help reduce pain? This may indicate the importance of social relationships and staying socially connected. A study was recently conducted by researchers at the University of California in Los Angeles.

In the study, the researchers asked 25 women to participate who had boyfriends with whom they had been in a good relationship for more than six months. The women received painful heat stimuli(刺激)to their forearms while they went through a number of different conditions.

In one set of conditions, they viewed photographs of their boyfriend, a stranger and a chair. “When the women were just looking at pictures of their partner, they actually reported less pain to the heat stimuli than when they were looking at pictures of an object or pictures of a stranger, ” said study co-author Naomi Eisenberger, director of UCLA’s Social and Affective Neuroscience Laboratory, “Thus, the mere reminder of one’s partner through a simple photograph was capable of reducing pain.”

In another set of conditions, each woman held the hand of her boyfriend, the hand of a male stranger and a squeeze ball. The study found that when women were holding their boyfriends’ hands, they reported less physical pain than when they were holding a stranger’s hand or a ball while receiving the same amount of heat stimulation.

“This changes our idea of how social support influences people,” Eisenberger said.

“This study proves how much of an impact our social ties can have on our experience and fits with other work emphasizing the importance of social support for physical and mental health,” Eisenberger added.

The researchers advised that the next time people are going through a stressful or painful experience, if they cannot bring a loved one with them, a photo may do.

Want to stay away from colds? Put on a happy face.

Compared to unhappy people, those who are cheerful and relaxed are less likely to suffer from colds, according to a new study. It's possible that being happy helps the body fight illnesses, say the researchers from New York University.

"It seems that positive feelings may reduce the danger of illness," said the study's chief researcher Sheldon Cohen.

In an earlier study, Cohen found that people who were cheerful and lively caught coughs and colds less often. People who showed feelings were also less likely to tell their doctors that they felt ill.

In this study, Cohen's interviewed 193 adults every day for two weeks. During the interviews, the people were given colds by doctors and had to stay alone in a room for six days.

The results showed that everyone in the study was equally likely to get ill. But for people who said they felt happy during the research period, their illness are less serious and lasted for a shorter time.

Cohen believes that when people experience positive feelings, their body may produce a chemical that helps fight illness and disease. So if you are worried abut your health, look on the bright side more often.

1.Which of the following was NOT a part of the study?

2.What did the study find?

3.According to Cohen, which of the following may help fight illness?

4.This passage is a/an         .

5.What is the best title for this passage?