问题补充：
I like tests, but now I like them very much.
A. usedn’t to
B. didn’t used to
C. didn’t use to
D. used to not
答案：
A. usedn’t to
B. didn’t used to
(答案→)C. didn’t use to
D. used to not
解析：be used to sth习惯于某事;used to do sth过去常常做某事,本结构中use是行为动词,以疑问句及否定句要借助于助动词.联系下文,但是我现在非常喜欢.可知上文意思是,我过去不喜欢考试.可知选C.
