--- Did you finish the book?
---Yes, I did. Thanks your dictionary, I had a better understanding of it.
A. reading, for
B. reading, to
C. to read, for
D. to read, to
网友回答
A. reading, for
(答案→)B. reading, to
C. to read, for
D. to read, to
解析：本题的含义是你看完那本书了吗？我看完了，幸亏由你字典的帮助我才对那本书有更好的理解。finish doing表示做完某事的意思，thanks to表示多亏或幸亏的意思，故本题选B。