You can't imagine wahat great trouble they have____the problem ____

问题描述:

You can't imagine wahat great trouble they have____the problem ____
A to solve ,being discussed B solving ;being talked about
C to solve,to talk about D solving,to discuss

A
have to do sth
BD的ing形和have不能搭配
being discussed现在分词被动式做定语修饰problem,表示正在被讨论的问题