[单项选择]The environment is everything that surrounds us: plants, animals, buildings, country, air, water--literally everything that can affect us in any way. The environment of a town, with its buildings and traffic and its noise and smells, where everyone is on top of everyone else, is a far cry from that of the countryside, with its fields and crops, its wild and domestic animals and its feeling of spaciousness. And the environment differs in different parts of the world.
Ecology is the science of how living creatures and plants exist together and depend on each other and on the local environment. Where an environment is undisturbed, the ecology of an area is in balance, but if a creature is exterminated or an unfriendly species introduced, then the ecology of the district will upset--in other words, the balance of nature will be disturbed.
Man is a part of the environment and has done more to upset the ecology during his short span on earth than any other living creature. He h
A. inform people about the science of ecology.
B. urge people to do something about the environment.
C. criticize some actions of human beings.
D. help us understand the world we live in.