求一篇英语书面表达,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约好下周去北京旅游,但你因故不能赴约.请根

Dear Tom,
I am so sorry that I cannot travel to Beijing with you next week. I have to stay in Shanghai because ...(eg. my dog has a fever, etc.). If it is possible for you to change to another date? Or also I could arrange my friend to pick you up in Beijing. Sorry for any inconvenience.
Best wishes
Hua Li