Dear David,

      At first, thanks for your invitation. I'd love to take part in your party next Tuesday morning. But I

am really sorry that I am too busy next week. On Monday I will have lessons all day and Tuesday I am

going to have a dancing lesson in the afternoon. On Wednesday, I am going to join Chess Club. And

on Thursday I will have a violin lesson in the morning. On Friday I will go to watch a movie with my

sister. On Saturday I will visit the Summer Palace and the Palace Museum. And on Sunday I am going

to go to the mall with mum in the afternoon. So I can't enjoy happiness with you and your friends. I hope

that next time I can visit you.

                                                                                                                               Yours,

                                                                                                                                 Mary

(答案不唯一)