引言:人类只有一个地球,而地球正面临着严峻的环境危机。我们看到外面的天空已不再像以前那样蔚蓝,河水已不像以前那样清澈,远处的那些高楼大厦像海市蜃楼一样隐隐约约。全球变暖、臭氧层破坏、酸雨、淡水资源危机、能源短缺、森林资源锐减、土地荒漠化、物种加速灭绝、垃圾成灾、有毒化学品污染等众多方面已成为威胁人类的主要环境问题。我们并不是继 Introduction: There is only one planet in mankind, and the earth is facing a serious environmental crisis. We see the sky outside is no longer as blue as before, the river is not as clear as before, those distant buildings like a mirage vaguely. Many aspects of global warming, the destruction of the ozone layer, acid rain, the crisis of freshwater resources, energy shortages, sharp declines in forest resources, land desertification, accelerated extinction of species, garbage and other toxic chemical pollution have become major environmental threats to mankind. We are not following