Fluorid
n. 氟化物
🗣️ 情景例句
This has been a long day.
这是个漫长的一天。
Whoever told you that was just joking.
无论是谁告诉你的，反正都是开玩笑。
After being absent from the Gables for a week,
一次，姑妈有一个星期没在“山墙庄园”住。