【正确答案】 A Letter of Thanks
Jan. 19th, 2013
Dear Prof. Smith,
I am writing to tell you how very kind of you to send me the list of reference books.
They are exactly what I need for my thesis.
When I was going through the book list yesterday, I realized how much time you have saved for me. As a matter of fact, I have been looking for those books in the library for quite a while, but without too much luck. Now here they are in the mail from a mentor as well as a friend.
I feel deeply indebted to you and I really don' t know how to thank you enough for your help.
Sincerely yours,
Li Ming
(114 words)

【答案解析】在第二段中所给出的感谢理由真实可信，这是应用文写作得高分的关键。