There are many people downstairs.What do you think ______?A.to happen B.happening C.is happened D.has happened 选哪个?为什么?
问题描述：
There are many people downstairs.What do you think ______?A.to happen B.happening C.is happened D.has happened 选哪个?为什么?
答
选D 这句话里的do you think是个插入语。简化后可以理解成： What has happened?(出什么事了？）
答
选D.do you think 是插入语,去掉以后就可以看出句中缺谓语,happen是不及物动词,不能用被动语态.