----Did the reference give the information you needed?
----Yes, but it, I had to read it entirely.
A. to find
B. having found
C. finding
D. find
网友回答
(答案→)A. to find
B. having found
C. finding
D. find
解析：句意：上文，这本参考书给了你你需要的信息没？下文，是的，但是要找到它，我不得不彻底地阅读。表示将来的动作，用不定式，选A。