众所周知,人类只有一个地球。保护环境要与社会公德、人格教育和实践行动联系起来。每个人都要履行保护环境的责任和义务。

Scientists warn that environmental problems are becoming more and more serious all over the world. With the development of industry and agriculture, cars make great noises and give off poisonous gas. Trees on the hills have been cut down, and waste water is being poured continuously into rivers.