谁帮我写个.假设你是新华中学的学生李华你和在上海上学的英国朋友TOm约好下周末去北京旅游,但你因故不

Dear Tom,
I am so sorry to tell you that I won`t be able to come with you for the trip to Beijing. Because I will have to take part in a speaking contest. can we fix another time?
Once again, I am so sorry and I wish you a pleasant time.
Yours Sincerely
Li Hua