人生存在一定的环境中，环境提供人类最基本的物质材料，满足人类最基本的生活需要。但人类的活动不可避免地改变着自然环境，打破了生态平衡。由于利用资源的盲目性，造成今日的环境危机：空气污染、水污染、水土流失等，影响人们正常的生活。现今，人们日益意识到这一危... Life in a certain environment, the environment provides the most basic human material, to meet the basic needs of human life. However, human activities inevitably change the natural environment and break the ecological balance. Due to the blindness of using resources, the environmental crises of today cause air pollution, water pollution and water and soil loss, which affect people’s normal life. Nowadays, people are increasingly aware of this crisis ...