 Dear Mr Smith, Thank you very much for invite me to go and stay with                           1. you in Nanjing.It’s the most beautiful city,and I have been                              2. eager to see you again.So I’m very sorry to tell you that I can’t                      3. go this summer vacation,since I’ve already been promised                              4. to stay with my grandmother in the countryside.She has                                 5. already 65 years old and miss me so much that I have no choice                      6. but do it.I’m busy preparing for my college entrance exams                                   7. all these days and I feel quite sure of myself.I wish I can go,                          8. and see you and Tom at the end this year.                                                     9. Best wishes to both you and Tom!                                                               10. Yours sincerely, Song Ping