写一篇初二水平的英语作文.
假设你是Cindy,你的好朋友Gina想邀请你下周去游长城,但是你因为下周的日程已经排满,不能前往.请根据下面表格给她写封回信委婉谢绝,并表达你的谢意.80词左右
Monday:Tostudyforamathtest
Tuesday:Topracticeplayingthepiano
Wednesday:Tolookaftermylittlesister
Thursday:ToprepareforMom'sbirthdayparty
Friday:Todomyhomework
Saturday:Todosomecleaning
Sunday:Togotoaconcert