Pericemental
[医] 牙周膜的
🗣️ 情景例句
Yes. This product will save you a lot of money and time.
是的。这个产品可为你节省很多的钱和时间。
That's quite all right.
没关系。
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）。