n.(護(hù)齒的)氟化物

It is a proven fact that fluoride strengthens growing teeth. 氟化物可以強(qiáng)化生長(zhǎng)中的牙齒，這是已證明的事實(shí)。

Since then, many studies have confirmed the value of fluoride. 從那以后，許多研究都證實(shí)了氟化物的價(jià)植。

The use of fluri fluoride to protect teeth is common in many parts of the world. 用氟化物來(lái)保護(hù)牙齒在世界許多地方很普遍。