knife是可数。knife的复数是knives。 knifen.刀；v.用刀伤害(或杀害) She was playing with a knife, so I took it away from her. 她在玩一把刀子，于是我...
knifen.刀；v.用刀伤害(或杀害)； 例如She was playing with a knife, so I took it away from her. She was playing with a knife, so I took it off her. ...
