假如你的朋友May邀请你（Sonia）周六去参加她的生日party。但你很忙，写一封电子邮件给她。向她表示感谢并说明你有一些什么事情要做（至少3件事），不能参加，但你准备了一份精美的礼物。

参考例文1：

Dear May,
Thanks for your invitation. I am sorry I can’t go. I am really busy. On Wednesday, I have a piano lesson. On Thursday afternoon, I have to see a doctor. On Friday, I am visiting my aunt. On Saturday, I am doing my homework. So I can’t come to your birthday party, but I have bought a nice present for you. I hope you will like it. Happy birthday to you!
Write soon!
Yours,
Sonia.

参考例文2：

Dear May,
Thanks a lot for inviting me to you birthday party. I hope I will have time to go, but I have been stressed out recently, I have so many things to do. On Monday, I have to study for a chemistry test. On Tuesday, I am going to see the doctor. On Wednesday evening, I have to visit my aunt. On Thursday, I will have a piano lesson. And on Friday, I have to babysit my little sister. On Saturday, I am doing my homework, So I can’t come to your birthday party, but I have bought a nice present for you. I hope you will like it. 
Write soon!
Yours,

sonia