邀请人：王力 被邀请人：John Smith 内容：王力及其妻子邀请John Smith夫妇来家中参加儿子一岁生日宴.时

June 4th,2010Dear Wang：Thanks too much for inviting us to join your son’s birthday party。I have seen the lovely baby before and it is worth celebrating for him and your happy family。But I regret that I cannot go to the party at that time。You know our company has a branch in America and it has something serious happened which needs my immediate decision。Thus I should go back as soon as possible。I am really sorry for my absence。Hope you will have a wonderful party and a good time。Sincerely,