题干
The______is a piece of metal，plastic or bone with teeth，used for tidying and arranging the hair．
A：comb
B：alarm
C：candle
答案(点此获取答案解析）
A
The______is a piece of metal，plastic or bone with teeth，used for tidying and arranging the hair．
A：comb
B：alarm
C：candle
的导数为（ ）
