I can't find the key to my office,I( )have lost it on my way home

问题描述:

I can't find the key to my office,I( )have lost it on my way home
A would B should C must D ought to

选C,译文是:我找不到我的钥匙,一定是掉在回家的路上了.
本题考的是虚拟语气的用法.
A:would have done是一般时的用法,不表推测.
B、D:should/ought to have done的用法是一样的,都表示本该做的事却没有做
C:must have done:表示推测,意思是“…一定在…”