求下面文章每段的大意 用一句话英语来概括
Man has been polluting the earth .The more people ,the more pollution.Many years ago,the problem was not so serious because 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 now slowly polluting the whole world .
Air pollution is still the most serious .It’s bad 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 more easily .
Many countries are making rules to fight pollution .They stop the people from burning 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 is caused by heavy traffic .It is sure 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 keep careful of the rise in pollution at the same time