抛物线y=a(x+1)(x-3)(a≠0)的对称轴是直线______.
y=a(x+1)(x-3)
=ax2-2ax-3a
由公式x=-b2a得,
抛物线的对称轴为x=1.
中国境内已知最早的人类是 ( )
A.北京人
B.半坡人
C.蓝田人
D.元谋人
The nurse is performing a neurologic assessment on a client during a routine physical examination. To assess the Bakinski’s reflex, indicate the point where the nurse would place the tongue blade to begin the stroke of the foot()
A. A
B. B
C. C
D. D