排水制度，山经过，低的国家脊，或沼泽的低的点，时常形成中级的控制。

Drainage systems, mountain passes, low points in ridges, or swamps in low country, often form secondary controls.

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组织实施排水许可制度；

to organize and implement the drainage permit system;

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组织实施排水许可制度；

to organize and implement the drainage permit system;

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