tooth的复数是teeth，变oo为eee。tooth的意思是牙齿，它的复数形式是不规则变化，需要特殊记忆。

tooth的复数使用例句

There is a tooth in the box.（改为复数）
There are some teeth in the box.

How often do you brush your teeth?
你多久刷一次牙？

He had nice square white teeth.
他的牙齿洁白而整齐，十分好看。

he had very pretty straight teeth.
她有一口漂亮整齐的牙齿。