题目内容：

There's apolice car in front of our neighbor's house.What do you suppose_____?
A .is happened B.has happened
C,would happen D.did happen

优质解答

选B.has happened
首先happen是不及物动词,不能用于被动,A选项排除.另外,do you suppose跟do you think/believe用法一致,位置比较随意.其实本来的句子应该是Do you suppose what ----.What--从句是作suppose的宾语.所以尽管句子是疑问句的形式,但是因为what后面是作为宾语从句,所以一定要用陈述句语序,不能倒装.所以排除d.
c的话表示虚拟,会发生什么.显然不合适.有警察肯定发生事情了.不需要虚拟的.