【答案解析】[参考范文]
Dear Mike,
I have arrived in Beijing yesterday and I want to show my gratitude to you for your hospitality. But I am sorry to tell you that I have brought the book with me back to China.
I had thought to return the book the night before I left, but I was so busy packing my luggage that I forgot to take it out from I suitcase. So I decide to send it back as soon as possible. Together with it is a CD of traditional Chinese music as a gift for you, which I hope that you will enjoy it very much.
I wish I had not caused too much trouble for you. Thank you again for the help you gave me during my stay in New York. Please tell me if you visit China some day and I can be your tour guide.

Sincerely yours,
Li Ming

[解析] 确定题型：道歉信的考查
确定主题：给在美国的房东写信，对将对方的书拿走表示歉意。