假如你是北京外国语大学英语系的主任，想邀请哈佛大学的Michael Hutchison教授来校为英语专业的研究生做一次有关美国文学的讲座，请用英语给他写一封120词左右的邀请函。
Dear Professor Michael Hutchison,
I' m Li Ming, dean of EngLish department of Beijing Foreign Studies University. We are very glad to hear that vou are attending an international conference in Beijing. We are writing this letter to inquire the possibility of inviting you to deliver a lecture on American literature for our postgraduate students on the evening of June 16. We have long noticed that you have done a lot of substantial and creative work in this field. Two of your books have become textbooks for our students for several years. So all of us believe your lecture will benefit our students and teaching staff alike. If you can manage to come, please tell us the number of your flight and we will meet you at the airport. If you can't make it, please also let us know. We are looking forward to your coming.
Yours sincerely,
Li Ming
