【正确答案】 Dear Prof,
I'm writing this letter to express my sincere thanks for your careful guidance during the writing of my thesis.
First and foremost, as a direct result of your efforts, my graduation thesis is awarded as an excellent one. Without your assistance, I'm afraid that I could have achieved nothing. What impressed me the most was your profound knowledge and thoughtful and thorough guidance. You are really a gem of a person to know.
I hope I have the opportunity of reciprocating. I will feel very honored and pleased if I can host you in the near future. I'm looking forward to meeting you next time.
Yours sincerely,
Li Ming

【答案解析】 本题要求写一封感谢信。感谢信的目的是向收信人表明谢意。信中要洋溢着感激之情，表示谢意的话要得体，既要符合被感谢者的身份，也要符合感谢者的身份，据上述要点，范文可安排如下：
第一段：表明写信意图，表示对什么的感谢。
第二段：说明道谢的具体原因。
第三段：再次致谢。