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- For one thing they keep the water clean. 一方面，他们可以保持水的清洁。
- ground water cleaning 地下水净化
- How can we make waste water clean? 我们怎样才能使废水净化呢?
- They did nothing to make the waste water clean. 他们没有采取措施净化废水。
- We must keep sea water clean and stop polluting it. 我们必须保持海水干净,停止污染。
- Seepage from land fills can pollute ground water or surface. 填土的渗漏可能污染地下水和地面水。
- Poisons used on farms and in homes can enter ground water. 在农场和家庭使用的毒物可以进入地下水。
- The quality of the ground water made some improvement. 地表水水质有所改善。
- This solution describes a spreading of a ground water mound. 这个解描述地下水丘的扩展。
- Ground water levels fall. Rivers get drier and drier. 地面水位下降。河流变得更干燥。
- Use clean water to remove dirt, and keep the water clean. 用干净的水去掉杂质，同时要保持水的干净。
- Ground water is also obtained for human use by sinking wells. 人们也通过挖井来获取地下水以供使用。
- Ground water is usually removed by man through wells. 地上水一般是由人们从井里汲上来。
- The flow of ground water is toward streams, lakes, or oceans. 地下水经流的方向是朝向河流、湖泊或海洋的。
- Recovery of ground water may require especially delicate tactics. 利用地下水，需要有特别完善的方案。
- Seepage from land fills can pollute ground water or surface water. 填土的渗漏可能污染地下水和地面水。
- The peak ground water level was analyzed on simulation. 仿真分析了地下水位的峰值。
- This filter moves dirt suspended in the water and keeps the water clean. 这个滤水器能去除水中残留的脏东西，保持水的干净。
- Dredging the river aims at keeping the river course smooth and water clean. 清挖河道是为了保持河道畅通，河水清洁。
- Ground water levels fall,rivers get drier and drier. 地下水位下降，河流越来越干涸。
