Life gets noisier every day and very few people can be free from noise of some sort or another. It doesn’t matter where you live-in the middle of a modern city, or a faraway village-the chances that you will be disturbed by jet aeroplanes, transistor radios, oil-powered engines, etc. are almost everywhere .We seem to be getting used to noise, too. Some people feel quite lonely without background music while they are working.
Scientific tests have shown that total silence can be very frightening experience for human beings. However, some people enjoy listening to pop music which is very loud, and this can do harm to their eardrums(耳鼓).The noise level in some disco is far above the usual safety level for heavy industrial areas.
A recent report about noise and concentration(专心) suggested that although a lot of people say that any noise disturbs their concentration, what really affects their ability to concentrate is a change in the level of noise. It goes on to say that a background noise, which doesn’t change too much (music, for example) may even help people to concentrate.
The best title for this passage is _______________.

A．Noisy Life	B．Background Noise
C．Disturbed Concentration	D．Changeable Noise

From this passage, the pollution of noise _______________.

A．doesn’t matter much	B．has become worse everywhere
C．has become better in big cities	D．has become better in villages

“Background music” in the passage means _______________.

A．music played in the concert	B．a kind of noise coming into your ears
C．music helps people to concentrate	D．music played while people are working

Some people may have their hearing hurt _______________.

A．while they are in completely silence	B．while they are dancing violently
C．while they are listening to loud pop music	D．while they are listening to soft music

Scientists have discovered that what prevents people from concentrating is _____.

A．any kind of noise	B．great changes in level of noise
C．background noise	D．various background music