Dear Mary's family,
I am writing this letter to express how grateful I am for your warm hosting over the last several weeks.Being a foreign student in your country,I was really homesick and not feeling comfortable.But you treated me as a part of the family selfishlessly and even took me to Chinese restaurant for welcoming dinner.I forgot about all the unhappiness because of you and had such a great time.I really appreciated your hosting,and I am looking forward to see you in China soon!
XX