Fluorid
n. 氟化物
🗣️ 情景例句
And your friends are planning to go to Columbia?
而且你的朋友们也准备上Columbia大学 ，对吗？
The day is long to him who knows not how to use it.
百无聊赖。
When shall we meet, this evening or tomorrow morning?
我们什么时间会面，今晚还是明天早晨？