Dear Mike,
Thank you for inviting me to go to movies next weekend.I'd like to go with you,but I have other things to do over the weekend.
To start with,I have to prepare for my coming English examination to be held in ten days.As you know,it is very important for me.
Secondly,I have to spare twp hours to escort my mother who is coming to school to see me.We haven't seen each other for a long time.I miss her very much.
Finally,I want to have a good rest in the dorm and try to be in goo spirits to go over my English lessons which the foreign teacher has given.
Best wishes.
Yours,
Joe
