Since the road is wet this morning,---------last night.

问题描述:

Since the road is wet this morning,---------last night.
A it must rain B it must have rainde C it must be raining D it must have been raining
选什么 为什么

B it must have rained
情态动词肯定推测句
因为这条路很湿,昨晚一定下雨了