If you are weak a subject, and asking a teacher for advice can help.
A. at; working hard
B. in; work hard
C. at; work hard
D. in; working hard
网友回答
A. at; working hard
B. in; work hard
C. at; work hard
(答案→)D. in; working hard
解析：句意：如果你在某一科不行，努力学习并向老师请求帮助可能有用。短语be weak in在……方面不行，be good at擅长……，现在分词作主语表示抽象的动作，结合语境可知选D。