Almost everyone knows that air pollution is (危险的) to people's health. However, not all people know that noise is a kind of pollution (也).

    A person who works and (居住) in a noisy place often talks in a loud (嗓音) so that other people can hear him. Lots of people living near airports can hardly hear anything. Many (年轻的) people in America can hear no better (比) old people, because they always listen to loud (流行的) music.

    What's more, machines and (小汽车) are producing much noise all the time. In China, the government is (努力) to do something to (阻止) the noise pollution, and return the good environment to people.