Monogen
单价元素
🗣️ 情景例句
Sometimes.
有时候。
Every extremity is a fault.
万事过分都差误。
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，