我猜你是要给他写封信表达你的意思是吧.如果是的话,可以这样写 dear (你朋友的名字), I am sorry to quarrel with you .I am really angry when you lost my book.But after I caim down,I thought that our friendship is more important than the book. so I wish you could forgive me .Can we jiust forget that and be friends as before? please call me. yours, Susan