具体如下：

Dear Andrew

How are you, my best friend Andrew? It is pleasured that you invited me to pay a visit to your home. But I am very sorry that I can’t accept your invitation because I have a very important competition which I must to take part in.

It is a competition of English play, which is hold once two years and will need a month to practice, is very valuable for me. So,I must take part in which I don’t want to miss the opportunity. Sorry, I believe you can understand me right?

Last, I want to give you a present that a CD about the hundredth anniversary of my school. It is too much fun in it and I hold you will be like. I promise you that I will accept your next invitation and bring some presents which you like.

Good Luck From Your Friend

Xiao xin

翻译：

亲爱的安德鲁：

你好吗，我最好的朋友安德鲁？很高兴你邀请我去你家做客。但很抱歉，我不能接受你的邀请，因为我有一个非常重要的比赛，我必须参加。

这是一场英语戏剧比赛，两年一次，需要一个月的时间练习，对我来说很有价值。所以，我必须参与其中，我不想错过这个机会。对不起，我相信你能理解我，对吗？

最后，我想送你一份关于我的学校一百周年纪念的CD。这太有趣了，我相信你会喜欢的。我向你保证，我将接受你的下一次邀请，并带来一些你喜欢的礼物。

祝你朋友好运

肖欣