俗话说“条条大路通罗马”，背诵
环保话题类
white pollute 白色污染
sustainable development 可持续发展
ecosystem 生态系统
environmental pollution 环境污染
over-fishing (overgrazing) 过度捕捞 (过度放牧)
sand storm 沙尘暴
resource exhaustion 资源枯竭
water and soil conservation 水土保持
soil erosion 土壤流失
clear-cutting (deforestation) 滥砍滥伐
desertification 沙漠化
conserve natural resources 保护自然资源
shortage of fresh water 淡水短缺
disruption of ecological balance 生态失衡
natural preservation zone 自然保护区