单项选择题
A.1 B.2 C.3 D.4
A.i=1,j=0 B.i=5,j=0 C.i=5,j=2 D.i=6,j=2
A.500,200,450,180 B.500,450,200,180 C.180,500,200,450 D.180,200,500,450