When people talk about air pollution, they are usually thinking about outdoor air _________. But do you know that there is also air pollution inside homes, offices, hotels and other buildings? The air in your home can be 2 to 100 times more polluted than the air outdoors! In fact, some American doctors say that 50% of the illnesses have _________ to do with polluted indoor air.

A lot of pollution comes from indoor activities _________ smoking and cooking. As most people _________ about 80%—90% of their time inside buildings, it is important _________ indoor air pollution seriously, too.

Air pollution influences (影响) our health _________. When the air is polluted, not only young children and old people suffer from (遭受) it, _________ people without health problems suffer as well. Indoor air pollution can _________ people’s eyes, noses and throats. Air pollution, both indoor and outdoor, can also _________ to lung cancer and heart disease! In the great London fog in 1952, 4,000 people died in a few days __________ the pollution! It is said that half a million young children and women die each year in India because of indoor air pollution!

As we know, we have only one earth. It is our home and it's also our duty to protect our home. We must take care of it. This means keeping everything clean on the earth.

Pollution is a " dirty " word. To pollute means to make things dirty. Pollution comes in many ways.We see it, smell it and drink it. Pollution is bad for our health and even our life. Man has been polluting the earth from the time he first made his food , washed his clothes in the river and threw his rubbish on the ground.

Many years ago, the problem was not so serious because there were not so many people. All the dirty things would soon be covered up. There was plenty of clean air, land and water. When the land was used up or the river was dirty in one place, men moved to another place. But this is no longer true. Man is now slowly polluting the whole earth.

At present（现在）, there are several kinds of pollution in the world. They are very serious. Such as air pollution, water pollution,noise pollution... However we are also glad to see that many people have known this and they are working hard to stop polluting the earth.

In today’s world, almost everyone knows air pollution is harmful to people’s health. However, not all people know noise is also a kind of pollution and is harmful to human’s health.

People who work and live in noisy conditions often go deaf. For example, many of the workers who print newspapers and books lose their hearing. Quite a few people living near airports also have hearing loss. Recently, it was reported that many teenagers in America can hear no better than 65-year-old people do, because these young people always listen to loud pop music.

   Making a loud noise in public is also a kind of pollution. It not only disturbs others but also does great harm to people’s hearing. Cars and machines also produce too much noise. Such pollution makes people feel uncomfortable and unpleasant, and it can even cause them to become sick or deaf. Nowadays, many countries are trying to solve all sorts of environmental problems, including noise pollution.