The internal and external pollution sources were major reasons to cause the eutrophication of lake water body.

外源污染和内源污染是造成湖体富营养化的主要原因。

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The internal and external pollution sources were major reasons to cause the eutrophication of lake water body.

外源污染和内源污染是造成湖体富营养化的主要原因。

youdao