A:Because his son escaped from school
B:His son’s escaping from school
C:His son escaped from school
D:What his son escaped from school
对实数a和b,定义运算“⊗”:a⊗b=a,a-b≤1b,a-b>1,设函数f(x)=(x2-2)⊗(x-x2),x∈R,若函数y=f(x)-c的图象与x轴恰有两个公共点,则实数c的取值范围是( )