The room is in a terrible mess；it（）have been cleaned for a long _英语解答

The room is in a terrible mess；it（）have been cleaned for a long time
书后答案是写的 mustn't 但是网上很多解释是应该填写can't 比较纠结,到底填写什么啊?

人气：243 ℃　时间：2020-03-28 04:07:08

解答

应该是can't mustn't 里含有禁止的意思,在英语中不能用于表示推测如：You mustn't smoke here 而can't 在此表示一种推测的不可能...