I am writing to extend my sincere gratitude for.。.I am writing to expre 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 don’t know how to thank you enough for your help.
I must thank you again for your generous help.
I am most grateful for your selfle donation.
My true gratitude is beyond the word’s de ion.
I feel most obliged to thank you once more.
Please accept my gratitude, now and always.