有道题选项里面有cut down和knock off.答案选的knock off,为什么不可以用cut down大概是这样的意思,原句不记得了.i know you want to buy my mp3.I cost 400 to buy it.,as it is not new,i'll______20% .用cut down不行吗?难

有道题选项里面有cut down和knock off.答案选的knock off,为什么不可以用cut down大概是这样的意思,原句不记得了.i know you want to buy my mp3.I cost 400 to buy it.,as it is not new,i'll______20% .用cut down不行吗?难 cut down sth和cut down on sth有什么区别 cut和cut down区别嗯嗯嗯 cut back和cut down的区别 cut down,cut down to,cut down on,cut off有什么区别 cut down Cut down cut down ? cut up,cut in,cut off,cut down有什么区别? cut down和cut down on 的区别（在线等） cut down后面可以跟doing吗 关于fall down/off 和cut down/off的用法 I have been asked to have the tree cut down.和I have been asked to cut down the tree.有什么区别么? cut off、cut down、cut away的区别 最好有解释呃 I was speaking to Anna on the phone when suddenly we were ______.选项: a、cut off b、cut down c、cut back d、cut out cut down/up/out He was cut ______ in his prime by cancer.a.off b.down c.out d.up越来越不懂了，词霸上的例句，用CUT OFF 和CUT DOWN 都有，到底选哪个啊？1.Many young soldiers were cut off in their prime.许多士兵都英年 sut sth into pieces 和 cut .out 和 cut sth down 的意思 cut down的意思 cut down trees at