---Do you mind my taking this seat? ---______.
A:No, of course not.
B:No, you can't take it.
C:Yes, take it please
D:Yes, sit down please
地图的类型多种多样,人们应根据需要选择常用地图,查找所需要的地理信息.读下列比例尺不同的三幅地图,回答问题.
a为常数,∀x∈R,fx=a2x2+ax+1>0,则a的取值范围是( )