题目内容：

Scientists believe that one of our most important means of knowing what is going on around us is the sense of sound. We are warned of danger by sounds. Sounds serve to please us in music. Sound has a waste product, too, in the form of noise. Noise has been called unwanted sound. Noise is growing and it may get much worse before it gets any better.

In order to know how noise affects people and animals, scientists have been studying for several years. They are surprised by what they have learned. Peace and quiet are becoming harder to find. Noise pollution is a threat that should be looked at carefully.

Sounds is measured in units called decibels (分贝). At a level of 140 decibels people feel pain in their ears.

Trucks , buses , motorcycles, airplanes, boats, factories---all these things make noise. They trouble not only our ears, but minds and bodies as well.

There is a saying that it is so noisy that you can’t hear yourself think. Doctors who study noise believe that we must sometimes hear ourselves think. If we don’t, we may have headaches, other aches and pains, or even worse mental problems.

Noise adds more tension (紧张) to a society that has already faced enough stress.

1.The sense of sound _________.

A. makes us feel excited

B. helps us hear more clearly

C. is something harmful to us

D. helps to know what is happening around us

2.When sound is turned into noise, ______________.

A. people grow worse and worse

B. it makes us forget all the past

C. people don’t know what to do with everyday life

D. it will be a kind of pollution to people

3.Why does the passage say peace and quiet are becoming harder to find?

A. Because the world is making more and more noise.

B. Because wars and battles happen here and there in the world.

C. Because all the sounds are becoming over 140 decibels.

D. Because some machines can make noise.

4.Doctors say we can hear ourselves think __________.

A. if we don’t like to hear noise

B. if we have no aches or pains in our bodies

C. if there isn’t too much noise

D. if we can’t be careful of noise