求英语作文一篇、初中水平、70词左右 内容如下：

Dear Gina,
Thanks for your invitation.I am afraid that I can't attend your birthday party this weekend..My parents has gone out for business and won't come back until next month.My grandmother is ill in bed,and I have to look after her at home.What's more,I am going to have an English test next week, and I am busy preparing for it.For these reasons,I can't go to your birthday party.I am so sorry.
Regards

Yours