单项选择题
A.0 B.10 C.20 D.出错
A. 7,2,5,4,3,6,1 B. 1,6,3,4,5,2,7 C. 7,6,5,4,3,2,1 D. 1,7,3,5,6,2,1
A.1,2,3,4,5,6,7,8,9,0 B.2,1,4,3,6,5,8,7,0,9 C.0,9,8,7,6,5,4,3,2,1 D.0,1,2,3,4,5,6,7,8,9