A. 2,3,1,6,8,7,5,4,10,9, B. 10,9,8,7,6,5,4,3,2,l, C. 1,2,3,4,5,6,7,8,9,10, D. 10,9,8,7,6,1,2,3,4,5,
A. O B. 2 C. 3 D. 5