分类：教育/科学-升学入学-高考
问题：英语选择题　hemusthavefinishedhishomew 
　he must have finish his homework fora long time,hasn't he?   hasn't  能不能用ｎｅｅｄｎ＇ｔ替换
回答：当然不可以了
must have done--- 对发生在过去但对现在造成影响的动作进行推测，用haven't/hasn't 
must have done  对过去的某一时间的事情猜测 ， 用didn't 
He must have read the novel yesterday,didn't he?