modern technology gives us conveniences, but it also has negative effects on our nature. We have to protect our environment, or we will have no trees, no clean air and water left for our children. Some people are destroying nature without knowing it, so we should tell them. Environmentalists, or people who want to improve or protect the environment, are concerned about these environmental problems and they have done many thing to tell others about them. If everyone is careful of the environment and tries not to destroy it, perhaps we can save the earth.