Dentoidin
[醫] 牙基質
??? 情景例句
Sorry, I'm afraid I'm busy tonight.
對不起， 今晚我恐怕沒空。
What does he do?
他是干什么的？
Now the other stuents open their eyes, and guess who has the eraser.
現在其余的學生張開眼，然后猜誰手里有橡皮擦。