i am writing to extend my sincere gratitude for...i am writing to express my thanks for...
i am writing to show my sincere appreciation for...i would like to convey in this letter my heartfelt thanks to you for...
i feel deeply indebted to you and i really dont know how to thank you enough for your help.
i must thank you again for your generous help.i am most grateful for your selfless donation.
my true gratitude is beyond the words description.i feel most obliged to thank you once more.please accept my gratitude, now and always.★例：
after being involved in an accident, you were looked after by another person. write a letter:
1) mentioning what happened in the accident,
2) telling the person about your recovery, and
3) expressing your thanks.
you should write with no less than 100 words on answer sheet 2. do not sign your own name at the end of the letter. use li ming instead. you do not need to write the address.
i am writing to thank you for looking after me after that unfortunate accident the other day, when i was knocked off my bike by a taxi. if it had not been for your assistance in giving me first aid and taking me to a nearby hospital, i fear that the consequences might have been much more serious
abundant thanks to each one of you for your patience, expertise and genuine concern. it was you who helped me believe in myself and gave me assurance that i could walk again. i would never forget each word you said to me and the things you have done to me. forgive me for the times i lashed out at you in frustration and thank you for understanding and remaining firm with me.
never stop your beautiful way of working with people. your help really means a lot to me and anyone who in trouble as well.