搜困为一些事情不能参加朋友的生日的英语作文

Dear friend,
Thank you for your asking. I would love to, but I am really a little bit busy that day. I have to do something important. I am very sorry that I can not go to the there. I'm really sorry about that, I would like very much to join you another time. I present to you the most sincere best wishes
Happy birthday to you! I hope you have a good time.
Yours,
Mary
亲爱的朋友，
十分感谢你的邀请。我非常想去，但是我那天真的有一些忙。我不得不去做一件重要的事。我非常遗憾我不能去。我真的非常抱歉,希望我下一次能够参加。在此对你献上最美好的祝愿。
生日快乐！我希望你玩得开心。

Hi Ben:
It is so nice to receive your invitation. It's my great honor to have the opportunity. I have been looking forward to celebrating my best friend's birthday party.
But what a pity since I was asked to participate in the Olymic competition on Jan 1st. I couldn't tell you how disappointed I was when I received that competition notice. Why is it the same day with my best friend's birthday? I have even thought of the surprise for you.
Here I am awfully sorry for not attending your party. A gift is delivered to your place and I hope you would love it.
Best wishes to you.