It is undeniable that the worsening environment has become the biggest concern of the present-day world. Land resources are dwindling because of water[复习必备 | 海量免费学习视频资源尽在“学而思轻课APP”>>>点击了解] loss and soil erosion. Waste gases poison the air we breathe. The rivers and lakes are polluted by waste dumped in them from factories. It is probably no exaggeration to say that deterioration of the quality of the environment threatens the existence of mankind itself.

Some people are of the opinion that the environmental problem is the price we have to pay for economic development. But I do not think that this argument is valid. After all， what is the point of economic growth if people's lives are adversely alfected by worsening environmental pollution？