response to playing and tickling, with sounds that can hardly be heard by people. Robert Provine, a scientist, who wrote the book, Laughter: A Scientific Investigation, said the new paper showed some important clues, like ape sounds that hadn't been realized before.

【语篇概述】科学家通过研究人类的笑和类人猿的笑来探索笑的进化。

6. Why did the scientists analyze the laughter made by tickling human babies and apes?

A. To try to discover if they can make characteristic sounds.

B. To see if they are interested in playing.

C. To find out if the laughter of apes and humans is related.

D. To find out the differences between humans and apes.

【解析】选C。细节理解题。根据第一段After analyzing the sounds, they concluded that people and great apes inherited laughter from a shared ancestor. . . 可知人类的笑和类人猿的笑有关联, 故选C。

7. Based on Paragraph 3 we can know that researchers measured the features in the sound to________.

A. find out ape sounds that hadn't been realized before

B. find out relations among primates' laughter

C. see what a family tree from each species looks like

D. make a report online in the journal Current Biology

【解析】选B。根据第三段第一句After measuring 11 features in the sound from each species, they tried to find out how these sounds appeared to be related to each other. 可知测量声音的目的是为了发现灵长目动物笑之间的关联。

8. What can be inferred from the last paragraph?

A. Panksepp spoke highly of the new research.

B. Rat laughter is likely to be related to ape laughter.

C. Robert Provine provided some new clues for the researchers.

D. Humans don't enjoy listening to ape laughter.

【解析】选A。推理判断题。根据最后一段第一句Panksepp, who studies laughter-like responses in animals but didn't participate in the new work, called the paper exciting. 可推断出Panksepp对这项研究评价很高。

9. What would be the best title for the passage?

A. Ape study explores evolution of laughter

B. Apes like to laugh when being tickled

C. Human laughter and ape laughter are different

D. Laughter: A Scientific Investigation

【解析】选A。主旨大意题。本篇文章主要介绍了科学家通过研究人类和类人猿的笑来探索笑的进化。

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 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 risk for obesity among people whose friends gained weight. And last year, Harvard researchers reported that strong social ties could improve