题干
假定你是李华，与留学生朋友Bob约好一起去书店，因故不能赴约。请给他用英语写封邮件，内容包括：
1）表示歉意；
2）说明原因；
3）另约时间。
注意：1）词数100左右。
2）可适当增加细节，以使行文连贯；
3）开头和结尾已为你写好。
Dear Bob,
Yours,
Li Hua
答案(点此获取答案解析）
Dear Bob,
I am sorry to say that I cannot go to the book store with you on Friday afternoon. I have just found that I have to attend an important class meeting afternoon. I hope the change will not cause you too much trouble. Shall we go on Saturday mo
