汤姆邀请李萍参加他这周日的生日宴会，但李萍的父母出差要到下个月回来，奶奶又卧病在床，需要人照顾。而且英语考试即将来临，因此李萍无法前去参加生日宴会。她感到十分抱歉，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___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
(快啊，急啊！今晚就要，来得及的加10分，最好自己写）
快啊，在线等！！！！！！！！！！！！！！！！！！！！！1
But I can't go to your birthday.Because my parents on a business trip to be back next month, grandmother sick in bed, need care. I am very busy recently, but also to review the English exam. I am very sorry, and here I wish you a happy birthday.
