题目内容：

I am writing this letter to express my regret that I can’t go to the Great Wall with you next weekend. It’s really pity. I feel sorry for them and want you to know that happened.

    Yesterday, my father, worked in the United States now, informed me that he would be back to home tomorrow. I was very happy when I heard the news. Father and I had not seen each other for two years, but I am really looking forward to this meeting.

    I sincere hope that you can be able to think in my position and accept my apology. I would appreciate your allowing me to make another dates to go to the Great Wall.

Once again, I am sorry for any inconvenience I have caused.