单项选择题

A well-documented body of information exists showing that noise can affect human in both physiological and psychological ways.
Hearing losses in particular occupations such as boiler-making and construction work are well known. In fact, however, we all find hearing more difficult as we age. Young ears can distinguish a wide range of sounds from low to very high frequencies, while older ears lose the ability to distinguish high-pitched sounds. A comparison of some industrialized versus non-industrialized people suggests that this hearing loss may not be the must-be result of old age.
Furthermore, a closer examination of other data reveals economic effects. For instance, airports are currently operating at less capacity because of noise regulations which restrict their hours of operation. Job performance can be seriously affected by loud noise, especially if accuracy and mental effort are involved. The use of outdoor areas for conversation is not possible for an estimated 5 to 10 million people who live or work in urban areas. When interference with television or speech or sleep is included, as many as 22 to 44 million people can be said to have lost part of the use of their homes and grounds because of noise. Thus noise pollution is a serious environmental concern. Much more effort should be made to warn people of the grave effects which may stem from an excessively noisy environment.

Because of the noise pollution, many airports（）

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