题干
There is a crowd of people in front of the house over there. What do you suppose
_____ there?
_____ there?
A：is happened
B：has happened
C：happening
D：to have happened
答案(点此获取答案解析）
B
、扬州评话、东北二人转以及南京白局、南京评话等曲种。这主要说明：（ ）