A:6s
B:4p
C:3d
D:4f
①5(a3)4﹣13(a6)2
②7x4•x5•(﹣x)7+5(x4)4﹣(x8)2
③(x+y)36+(x+y)92
④(b﹣3a)2n+1•(3a﹣b)2n+13(n为正整数)