A:how we can be on time
B:what we are going to do
C:why we get to school late
D:if we will arrive at the meeting on time
已知函数fx=13x3+ax+2bx+c有两个极值点x1,x2且x1,x2满足﹣1<x1<1<x2<2,则直线bx﹣(a﹣1)y+3=0的斜率的取值范围是( )