简答题:Suppose you were invited by Professor William to work as an assistant in his new program, but you had a plan for writing a paper. Write an email to him to refuse his invitation, make an apology, and recommend your roommate to him.
You should write about 100 words neatly on the ANSWER SHEET.
Do not sign your own name at the end of the email. Use "Li Ming" instead. (10 points)

Dear Professor William,
I was so glad when I received your invitation to work as your assistant in your new program, which is my long-cherished dream. However, it is a great pity that I have to work for my graduate paper and I can hardly spare time to do other work.
I am sorry to tell you about this, and please accept my heartfelt apology, I really hope it will not affect your work plan. If you still need a capable assistant, I would like to introduce Zhang Wei, one of my roommates, as an ideal candidate to you. As far as I know, his qualifications can meet your requirements. Four years of university study equips him with relevant knowledge about data processing and he's got a good command of English, which fits him perfectly for the job.
Once again, please accept my apology for any inconveniences that may occur. I am looking forward to your reply.
                                                                                                                                           Yours sincerely,
                                                                                                                                                 Li Ming