Fluorination
n. 氟化作用
🗣️ 情景例句
I have no time for extra-curricular activities.
我可没时间参加课外活动。
I invited him to come over, but he wouldn't.
我请他过来，但是他不肯。
I really enjoy it, but I'm tired of so much reading.
我可喜欢学啦！但要读的东西太多，我很烦。