阅读理解。 In today's world, almost everyone knows that air pollution and water pollution are harmful to people' health. However, not all the persons know that noise is also a kind of pollution, and this is harmful to people' health, too. People who work and live under noisy conditions usually become deaf today. However, scientist believe that 10 percent of workers in Britain are being deafened by the noise where they work. Many of the workers who print newspapers and books, and who weave cloth become deaf. Quite a few people living near airports also become deaf. Recently it was discovered that many teenagers in America could hear no better than 65-year-old persons, for these young people like to listen to pop music and pop music is a kind of noise, Besides, noise produced by jet planes or machines will make people ill or even drive them mad. It is said a continuous noise of over 85 decibels can cause deafness. Now the government in many countries have made laws to control noise and make it less than 85 decibels. In China, the government is trying to solve not only air and water pollution problems but also noise problems. 1. Today scientists believe that _______. A. 90 percent of all the workers in Britain are not suffering from (受折磨) noise B. 10 percent of all the workers in Britain are working in noisy places C. the hearing of 10 percent of all the workers in Britain are being deafened by the noise where they work D. 90 percent of all the workers are free from any noise 2. Those who usually ________ have poorer hearing. A. weave cloth B. print newspapers C. live near airports D. all the above 3. Recently many teenagers could hear even worse than 65-year-old people in America, because _______. A. they are too young to hear anything clearly B. their ears are still too small C. they haven't trained their hearing D. they listen to 'pop' music too much 4. According to the passage, a continuous noise of _______ decibels can make you deaf. A. 85 B. less than 85 C. more than 85 D. only 85