there are many people downstairs .what do you think ____ Ato happen B happening Cis happened Dhas

问题描述:

there are many people downstairs .what do you think ____ Ato happen B happening Cis happened Dhas

C

应该是D
选项是:has happened 吧?

D has happened
do you think 是插入语.可以拿掉不影响句子结构.
故A项结构不完整,B项少了is C项错误,happen无被动
选D what has happened 发生了什么