dear mary，

i would like to take this opportunity to express my heartfelt gratitude to you for your help when i was in difficulty。 you have been very kind and helpful since we knew each other。

last week， i caught a bad cold and had to stay at home for a week。 when i was worrying about the lessons， you came to my home after school and helped me with every subject。 with your help， i didn’t fall behind others。

again， thanks so much for your enthusiastic help。 even though you are to about to go abroad for further education i know that i will always stay in touch with you。 i wish you every success in the future and i hope we can exchange more viewpoints on study。

please keep in touch， and drop in and visit us whenever you are in this part of the world。

very sincerely

peter