英语问题do you know where david is

题目

英语问题do you know where david is
Do you know where David is?I couldn`t find him anywhere.
-Well.He( )have gone far-his coat is still here.
A shouldn`t Bmustn`t C can`t D wouldn`t
should不是也可以表示推测吗,为什么答案是C而不是A呢?

答案

should (not) have done 表示本(不)应做某事,现在却(没)做了,带有责备语气
must/can have done 都表示肯定推测,must语气更为强烈
本题中,有推测依据his coat is still here,故用can't