Fluoridating
v. 在饮水中加少量之氟（以防儿童蛀牙）( fluoridate的现在分词 )
🗣️ 情景例句
I had never been there before.
我以前从来没有去过那里 。
He's been out of a job for months.
他已经失业好几个月了。
Thanks.
谢谢。