Lactomucin
乳粘蛋白
🗣️ 情景例句
I'm going to the library to do some research.
我要去图书馆搞些调研。
We used to have a lot of fun when we were that age.
当我们是变老时，我们过去常有很多趣事。
Good morning, sir.
先生，早上好。