根据语篇情景，用恰当的短语或句子填空，使之意思完整。

Dear Henry,

     Thank you for your invitation. I am sorry I can't visit you this week. I am really busy. Tomorrow I

have to __1__. You know, my mother wants me to be a pianist (钢琴家). On Wednesday, I have to

__2__. Our math teacher is very strict with us and hopes we get good grades. On weekends, I have to

__3__. My parents are both out this weekend, leaving my little sister and I at home. She is much younger

than I .What a busy week!

                                                                                                                       Write soon!