Usea
[医] 脲, 尿素
🗣️ 情景例句
The pleasure is all mine.
这是我的荣幸。
Knowledge advances by steps not by leaps.
知识的获得是循序渐进而不是突飞猛进的。
Imagine a pen attached to the weight in such a way that its point rests upon a piece of paper on the floor.
假定把一支笔拴在重物上，笔尖落在地板上的一张纸上，