第1个回答 2013-09-20
楼主， 你好It must have rained last night, because the ground is wet望采纳！
第2个回答 2013-09-20
It must have rained last night, because the ground is wet.
第3个回答 2013-09-20
It must have rained last night, for the ground is wet.
第4个回答 2013-09-20
It must rain last night , because the ground was wet.
第5个回答 2013-09-20
It must rain yesterday,because the ground is wet.