解析：设圆锥母线长为R，底面圆的半径为r，则r＝Rsin.又底面周长l＝2πr＝Rα，即2πRsin＝Rα，∴α＝2πsin.

∵＜θ＜，∴＜sin＜，∴π＜α＜π.

答案：D

设函数f(x)(x∈R)满足f(－x)＝f(x)，f(x)＝f(2－x)，且当x∈[0,1]时，f(x)＝x³.又函数g(x)＝|xcos(πx)|，则函数h(x)＝g(x)－f(x)在上的零点个数为                                                                    (　　)

A．5                               B．6

C．7                               D．8