what do you _________today?
问题描述：
what do you _________today?
A is the biggest danger to our environment
B has the environemnt been damaged by
C has the factory harmed the environment
D has the greast harm been done to the environment
BCD为何不选?
答
do you后面是不是少了一个think
如果是的话,那么全句是：What do you think___ today
do you think 作为插入语,后面只能接陈述句的语序,整个句子去掉do you think之后就是一个陈述句：What is the biggest danger to our environment today.
这是一个完整的陈述句,其他的不行,所以选A.是不是插入语后面都用陈述句语序是的，你在理解的时候可以去掉插入语，看下是不是陈述句语序。