A
There is an old saying in English: “Laughter is the best medicine”．Until recently, few people took the saying very seriously.Now, however, doctors have begun to investigate laughter and the effects it has on the human body.They have found evidence that laughter really can improve people's health.
Tests were carried out to study the effects of laughter on the body.People watched funny films, while doctors checked their heart rate, blood pressure, breathing and muscles.It was found that laughter has similar effects to physical exercise.It increases blood pressure, the heart rate and the rate of breathing; it also works several groups of muscles in the face, the stomach, and even the feet.If laughter exercises the body, it must be beneficial.
Other tests have shown that laughter appears to be capable of reducing the effect of pain on the body.In one experiment doctors produced pain in groups of students who listened to different radio programs.The group, which tolerated the pain for the longest time, was the group, which listened to a funny program.The reason why laughter can reduce pain seems to be that it helps to produce endorphins (内啡肽)in the brain.These are natural chemicals that diminish both stress and pain.
There is also some evidence to suggest that laughter helps the body's immune (免疫的) system, that is, the system which fights infection.In an experiment, one group of students watched a funny video while another group served as the control group—in other words, a group with which to compare the first group.Doctors checked the blood of the students in both groups and found that the people in the group that watched the video had an increase in the activity of their blood cells, that is, the cells which fight infection.
As a result of these discoveries, some doctors and psychiatrists (精神病学家)in the United States now hold laughter clinics, in which they try to improve their patients' conditions by encouraging them to laugh.They have found that even if their patients do not really feel like laughing, making them smile is enough to produce beneficial effects similar to those caused by laughter.
【语篇解读】 本文是一篇说明文。文章主要讲述的是医生们研究笑对人体的影响，并且发现了笑确实可以改善人们的健康。
1．We learn from the first paragraph that laughter ．
A．is good for one's health
B．is related to some illness
C．has been investigated long since
D．has no effect on the body
A [细节理解题。根据第一段中的“Now, however, doctors have begun to investigate laughter and the effects it has on the human body.They have found evidence that laughter really can improve people's health.”可知，笑对人们的健康是有好处的，故选A。]
2．Doctors have found that laughter ．
A．keeps down blood pressure
B．has similar effects to physical exercise
C．decreases the heart rate
D．increases stress
B [细节理解题。根据第二段中的“It was found that laughter has similar effects to physical exercise.”可知，选B。]
3．Which of the following statements is NOT true of laughter according to the passage?
A．It reduces pain.
B．It exercises the body.
C．It improves the body's immune system.
D．It can cure cancer.
D [细节理解题。根据第二段中的“It was found that laughter has similar effects to physical exercise.”，第三段中的“Other tests have shown that laughter appears to be capable of reducing the effect of pain on the body.”和第四段中的“There is also some evidence to suggest that laughter helps the body's immune system, that is, the system which fights infection.”可知，A、B、C三项都是正确的，文中并未提到笑可以治愈癌症，故选D。]
4．In a laughter clinic, doctors ．
A．laugh at their patients
B．encourage their patients to laugh
C．smile when they don't feel like laughing
D．never stop laughing
B [细节理解题。根据最后一段中的“As a result of these discoveries, some doctors and psychiatrists in the United States now hold laughter clinics, in which they try to improve their patients' conditions by encouraging them to laugh.”可知，在笑声诊所里，医生们鼓励他们的病人去笑，故选B。]
