纯手写,仅供参考.
Dear XXX,
I 'm very sorry for losing the book I borrowed from you two days ago.（第一句表达你的歉意）For I went to a public library and forgot to take the book.(这句话是说你怎么弄掉的,随便编) I promise I will buy you a new one tomorrow without fail.Sorry again.（这句是承诺你怎么样补偿别人）
Yours XXX（署名）
Jan.17,2011