问题 单项选择题

细菌虽然小得肉眼看不见,但它们在分解枯枝嫩叶的过程中确实起到“关键性的作用”。它们能将吸收二氧化碳和其他养分而长成的树干与枝叶,再分解成二氧化碳释放到大气中。若没有细菌的存在,那么地球上的二氧化碳只能维持植物利用40年,因为碳素将被锁定在植物体内而不能参与到物质循环中去。由于细菌的这种作用,维持了整片森林甚至整个地球的盎然绿意。 下面对文章中“关键性的作用”解说不正确的一项是( )。

A.细菌在分解树干枝叶的过程中将它吸收的二氧化碳释放到大气中去

B.细菌在分解枯枝的过程中释放了二氧化碳,维持了地球上的物质循环

C.细菌把有可能被锁定在植物在植物体内的碳素分解出来并释放到大气中去

D.如果没有细菌作分解枯枝的工作,地球将无法维持盎然的绿意

答案

参考答案:A

解析: 材料提到,“它们能将吸收二氧化碳和其他养分而长成的树干与枝叶,再分解成二氧化碳释放到大气中。”A项错误在“细菌吸收的二氧化碳”,而根据材料,是细菌把枯枝叶分解成二氧化碳的。

完形填空

第二节(共5小题;每小题2分,满分10分)

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项多余选项。

There is an English saying, “Laughter is the best medicine.”51   Now, however, doctors have begun to look into laughter and the effects it has on the human body. They have found 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, blood pressure, breathing and muscles. 52  It increases blood pressure, the heart beating and 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.

53 In one experiment doctors produced pain in groups of students who listened to different radio programmes. The group that tolerated (忍受)the pain for the longest time was the group which listened to a funny program. 54 

In this way55   they help to improve their patients’ condition by encouraging them to laugh. They have found that even if their patients do not really fell like laughing, making them smile is enough to produce beneficial effects similar to those caused by laughter.

A.The reason why laughter can reduce pain seems to be that it helps to produce a kind of chemicals in the brain which diminish both stress and pain.

B.Until recently, few people took the saying seriously.

C.Laughter and physical exercise have similar effects on the human body.

D.It was found that laughter has similar effects to physical exercise.E. As a result of these discoveries, some doctors in the United States now hold laughter clinics.

F. Laughter could produce a kind of chemical.

G. Other tests have shown that laughter appears to be able to reduce the effect of pain on the body.

问答题 简答题