It last night for the ground is wet now.A. might not have rainedB. must have rainedC. co

问题补充：

It last night, for the ground is wet now.

A. might not have rained

B. must have rained

C. couldn have rained

D. rained

答案：

A. might not have rained

(答案→)B. must have rained

C. couldn have rained

D. rained

解析：对过去的事情肯定推测应用：must have +过去分词。