很多动物身上有成对的附肢，一侧一个，这是很普遍的现象。

Paired appendages, with one on each side of the body, are common in many animals.

youdao

很多动物身上有成对的附肢，一侧一个，这是很普遍的现象。

Paired appendages, with one on each side of the body, are common in many animals.

youdao