Fluoridizing
v. 用氟化物处理( fluoridize的现在分词 )
🗣️ 情景例句
They're the ones.
找他们没错。
There are 16 participants here today.
今天有16位参会者。
and a period (which is the time it takes a wave crest to travel one wave length).
和周期（浪峰走过一个波长所需的时间）。