敬爱的李先生: 很抱歉我不能参加下周六您和您夫人为您兄弟举办的晚宴,因为那天晚上我恰巧有约在先。但我非常感激您邀请我,并希望在不久的将来有机会能见到您的兄弟。Ladies and gentlemen, First of all, allow me to thank you all for your invitation to attend this party.Im greatly pleased to have a chance to visit your great country and meet with so many of her people. Dear Mr. Lee,I am so sorry that I cannot come to the dinner you and Mrs. Lee are giving next Sunday for your brother because of a previous engagement on that evening.I do