You can't imagine wahat great trouble they have solving____the problem ____You can't imagine what great trouble they have solving the problem ____ 1.being talked about 2.being discussed

You can't imagine wahat great trouble they have solving____the problem ____You can't imagine what great trouble they have solving the problem ____ 1.being talked about 2.being discussed
You can't imagine wahat great trouble they have solving____the problem ____
You can't imagine what great trouble they have solving the problem ____
1.being talked about
2.being discussed

You can't imagine wahat great trouble they have solving____the problem ____You can't imagine what great trouble they have solving the problem ____ 1.being talked about 2.being discussed
选2 talked about 是及物动词词组 后面须跟宾语

选2 the problem 和 discuss是被动关系 being discussed做定语修饰the problem

第二个