M. m.
[医] 粘膜
🗣️ 情景例句
It's too hard to explain.
这很难解释清楚。
I'm a new employee.I was hired yesterday.
我是昨天被雇用的新雇员。
Don't touch anything unless your teacher tells you to.
除非老师允许，否则你不要动任何东西。