x
…
﹣4
﹣3
﹣2
﹣1
0
1
y
﹣37
﹣21
﹣9
3
①当x>1时,y随x的增大而增大 ②抛物线的对称轴为直线x= 12 .
③当x=2时,y=﹣1 ④方程ax2+bx+c=0一个负数解x1满足﹣1<x1<0.
Good books are like wise friends, because _____ support you to walk forward and help you understand the world.
下列有关光现象的说法中,正确的是( )