问题补充:
—What’s the matter with you? You look so worried.
-- I don’t know the problem.
A. what to solve
B. how to solve
C. to solve what
D. how can I
答案:
A. what to solve
(答案→)B. how to solve
C. to solve what
D. how can I
解析:根据上文句意,你怎么了?你看起来这么焦虑。——我不知道如何解决这个问题。What意思是什么,指具体事物。How是怎么怎样的意思,指方式。根据题意可知这是说的是解决问题的方式,选项D缺少谓语动词,故选B。