—I think it is going to be a big problem.—Yes it could be.—I wonderwe can do about it.A

问题补充：

—I think it is going to be a big problem.

—Yes，it could be.

—I wonderwe can do about it.

A. if

B. how

C. what

D. that

答案：

A. if

B. how

(答案→)C. what

D. that

解析：本题考查名词性从句的连接词的用法。wonder后面应跟宾语从句，而从句中的谓语动词do是及物动词，可见从句缺少一个代替宾语的成分，我们可以用排除法排除不作成分的if和that，再排除引导方式状语的how，答案是C，句子的意思是“我们能就此做些什么”。