完形填空

　　The world itself is becoming much smaller by using modern communication means (通讯). Life today is much easier than it was hundreds of years ago, but it has brought new 1 ．One of the  2 is pollution (污染). To pollute means to make things  3 . Pollution comes in many ways. We see it, smell it, drink it and even hear it.

　　Man has been polluting the earth. The more people, the more pollution. Many years ago, the problem was not so serious  4 there were not so many people. When the land  5 or the river was dirty in a place, men moved to another place. But this is no longer true. Man is now slowly polluting the whole world.

　　Air pollution is still the most serious. It's  6 to all living things in the world, but it is not only one kind of pollution. Water pollution kills our fish and pollutes our drinking water. Noise pollution makes us become angry  7 .

　　Many countries are making rules (法规) to fight pollution. They  8 the people from burning coal (煤) in houses and factories in the city, and from blowing dirty smoke into the air.

　　The pollution of is now the most dangerous problem of  9 pollution. It is caused (引起) by heavy traffic. It is  10 that if there are fewer people driving, there will be  11 air pollution.

　　The  12 is our home. We must take care of it. That means keeping the land, water and air clean. And we must keep careful of the rise in pollution at the same time.

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