Beavers often build DAMS to keep the water of the pond at a constant level.

河狸常常修筑堤坝，使水塘的水位保持不变。

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Beavers often build DAMS to keep the water of the pond at a constant level.

河狸常常修筑堤坝，使水塘的水位保持不变。

youdao