语法选择The world itself is becoming much smaller by using modern traffic and modern communication means. Life today is 1 easier than it was hundreds of years ago, but it 2 new problems. One of the biggest is pollution. To pollute means to make things dirty. Pollution comes in many ways. We 3 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 was used up or the river was dirty in a place, men moved to another place. But this is no longer true. Man is slowly polluting 5 whole world.
Air pollution is still the most serious. It's bad to all living6 in the world, but there is not only one kind of pollution. Water pollution kills our fish and pollutes our drinking water. Noise pollution makes us7 angry more easily.
Many countries are making rules to fight pollution. They stop people from 8 coal in houses and factories in the city, and from blowing dirty smoke into the air.
The pollution of SO2 is now the most dangerous problem of air pollution. It 9 by heavy traffic. It is certain that if there are fewer people driving, there will be less air pollution.
The earth is our home. We must take care of it. That means keeping the land, water and air clean. And we must be careful of the rise in population 10 the same time.
