Dear Prof. ***,
I have not contacted you for a long time. Because I am exhausted by thinking over my application and camparing my offers with each other. I was informed by another top University that I am awarded a RA(the stipend is $17,460 per year and tuition waived). Because your offer will give me a TA with waived tuition fee($1,425 per month for 9 months only if I get a mark more than 230 in TSE, otherwise, I can only get $1,000 per month).
Some friends told me that it is almost impossible for a new Chinese student to pass this test at the first year. It means I can only get $9,000 first year. I think it may not cover my expense in OSU. So after careful considerasion, I am very sorry to tell you that I am not able to accept your offer, though I always regard your supervision as my first choice and the key of my future achievement.
It is not easy for me to write this email. It was you who helped me re-send my application stuff and get a special dealing, otherwise, I may not get this offer from OSU. I really hope you will forgive me for changing my mind, and I sincerely hope it will not cause too much inconvenience to you. If I have the chance to meet you in US someday, I will always regard you as my mentor.
It is hoped that this notification reach you early enough for a rearrangement. Thank you again for all the assistance you have given to me during my application.