2.说明原因；
3.另约时间。
注意：
1.词数100左右；
2.可以适当增加细节，以使行文连贯。
范文：
dear bob,
i’m sorry to say that i cannot go to the bookstore with you on friday afternoon. i have just found that i have to attend an important css meeting that afternoon. i hope the change will not cause you too much trouble.
shall we go on saturday morning we can set out early so that we’ll have more time to read and select books. if it’s convenient for you, let’s meet at 8:30 outside the school gate. if not, let me know what time suits you best. i should be avaible any time after school next week.
yours,
li hua
译文：很抱歉，我不能和你一起去书店星期五下午。我刚刚发现我要参加一个下午的重要的课堂。我希望这个变化不会给你带来太大的麻烦。
我们星期六上午去好吗？我们可以早出发，以便我们有更多的时间来阅读和选择书。如果方便的话，我们8:30在校门口见面。如果没有，让我知道什么时候最适合你。我应该在放学后的任何时间都在学校。
【2016天津高考英语卷】
(书面表达)假设你是晨光中学学生会主席李津，你校拟向美国友好交流学校的中文班捐赠一批图书。请根据以下提示，写一封邮件与中文班班长chris联系，并告知将于今年七月赴对方学校参加夏令营时带去赠书。
(1)自我介绍；
(2)拟捐赠图书的类型、册数、用途等；
(3)询问对方的其他需求。
注意：
(1)词数不少于100；
(2)请适当加入细节，使内容充实、行文连贯。
参考词汇：学生会 the student union
dear chris,
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
yours，
li jin
范文：dear_chris，
how is everything going i am li jin, president of the student union from chenguang middle school. now i am writing an e-mail to tell you something about our donated books.
we will go to take part in the summer camp held by your school this july, which makes us very excited. at the same time, we are going to bring along about five hundred books with us for your css. most of them are about chinese and some about chinese cooking as well. i believe these donated books will not only make you more familiar with china but help enhance your chinese.
by the way, if you need any other kind of books, please do t
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