Bipositive
[医] 二正[原子]价的
🗣️ 情景例句
Ms Lin worked hard all year.
林小姐一年到头辛勤工作。
He that would eat the fruit must climb the tree.
不劳无获。
and it is only in the seas and rivers, and sometimes lakes, where mud and sit have been continuously deposited,
所以只有在泥沙不停淤积的海洋和江河里，有时在湖泊里，