双眼的视觉贡献实际并不均衡，用拇指遮住目标，看不见目标的眼称为（）。
A、健眼
B、辅助眼
C、好眼
D、优势眼
参考答案：D
f（x）=ax2-2ax+2+b（a＞0），f（x）在[2，3]上最大值是5，最小值是2，若g（x）=f（x）-mx，在[2，4]上是单调函数，求m的取值范围．
33. _______, I have never seen anyone who’s as capable as John.
A．Long as I have travelled
B．As I have traveled so much
C．Much as I have traveled
D．As I have traveled so long
