结构要点:
介绍信是向收信人介绍某人的信件，包含三个部分：
1． 说明被介绍人的身份；
2． 提出希望收信人做的事情；
3． 如果是请收信人关照被介绍人，表示感谢；如果是请收信人与被介绍人共同工作，则对合作表示乐观。
Directions 19
Suppose that your friend is going to stay at a big city. Write a letter in about 100 words to introduce her to a friend there. Do not sign your own name at the end of your letter, using "Li Ming" instead.
Sample:
Dear Linda,
I want to introduce to you the bearer of this letter, Helen Herbert, who is a diligent and intelligent scholar just like you. She will attend an international conference on economics from August 27 through August 30 at the ShangriLa Hotel of your city.
She will have no problem with her accommodation. I am sure a talk will benefit both of you a lot. I have given your mobile phone number to her, and I hope it will not cause any inconvenience for you.
Thank you for your kindness and consideration.
Sincerely yours,
Li Ming
