[单项选择]

C
The world itself is becoming much smaller by using modem traffic and modem communication means. Life today is much easier than it was hundreds of years ago, but it has brought new problems. On, of the biggest is pollution. To pollute means to make things dirty. 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 many people. When the land was used up or the river was dirty in one place, man 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 for all living things in the world, but it is not the only one kind of pollution man makes. Water pollution kill our fish and pollutes our drinking water. Noise pollution make us angry more easily.
Many countries are making rules to fight pollution. They stop people fro
A. because the earth is being polluted day and night
B. thanks to science development
C. because of the rise in population
D. because the earth is blown away by the wind every years