〖题目〗根据提示写一封60~80字的信。

　　Tom 邀请Li Ping 参加他这周日的生日宴会，但Li Ping的父母出差要到下个月回来，奶奶又卧病在床，需要人照顾。再说英语考试即将来临，因此，无法前去参加生日宴会。Li Ping感到很抱歉，只好写信辞谢。

　　Dear Tom，

　　Thank you very much for inviting me to your birthday party。 I‘d love to go but I can’t。

　　My parent ____________________________________。 From Li Ping

　　〖范文〗

　　Dear Tom，

　　Thank you very much for inviting me to your birthday party。 I‘d love to go but I can’t。 My parents are out on business。 They are coming back next month。 And now I have to look after my grandma because she is ill in bed。 And I also need to study for my coming English exam。 I‘m very sorry but I can’t go to your party。 Thank you for asking me。 I hope you can have a good time。