Blocking a river with a dam also blocks the movement of fish upstream to spawn and the movement of silt downstream to fertilise fields.

用大坝阻断河流使得鱼类无法逆流而上去产卵，同时淤泥无法顺流而下去肥沃土地。

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Blocking a river with a dam blocks the movement both of fish upstream to spawn and of silt downstream to fertilise fields.

建堤坝来阻断河流，既阻挡了回流产卵的鱼，又阻碍了下游淤泥肥沃土壤。

youdao

Blocking a river with a dam blocks the movement both of fish upstream to spawn and of silt downstream to fertilise fields.

建堤坝来阻断河流，既阻挡了回流产卵的鱼，又阻碍了下游淤泥肥沃土壤。

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