A:So I did
B:I did so
C:So do I
D:So did I
竖式计算
806﹣279=
453+556=
168×4=
76÷8=
102×9=
350×6=
645+387=
864﹣328=
若要使房子周围的门窗都朝南,房子只能建在( )