—_________ did the students in Grade Nine study so hard ? —To make their dreams come true.

9.—_________ did the students in Grade Nine study so hard ?
—To make their dreams come true.
A. Why B. Which C. Who D. What
【答案】A
【解析】
【详解】句意：——为什么九年级的学生学习那么努力？——为了使他们的梦想实现。A. Why为什么；B. Which哪个；C. Who谁；D. What什么。根据下文To make their dreams come true.可知上文是用why来提问。根据题意，故选A。