The ground is all wet. It ______ last night.
A.can’t have rained
B.may have rained
C.can have rained
D.must have rained
网友回答
D解析考查情态动词表推测。时间是last night，所以要用情态动词加完成时态表对过去事实的推测。can’t have rained表不可能下雨，和前一句矛盾，排除A；may have rained可能下雨了，把握性不大，和前一句不符，排除B；can不能用于肯定句表推测，排除C；所以选D，must have rained肯定下雨了，把握性很大，符合句意。