—I asked her .
A:if is she cooking for lunch
B:if she is looking for lunch
C:what did she cook for lunch
D:what she cooked for lunch
如图,抛物线y=ax2+bx+2与坐标轴交于A、B、C三点,其中B(4,0)、C(﹣2,0),连接AB、AC,在第一象限内的抛物线上有一动点D,过D作DE⊥x轴,垂足为E,交AB于点F.
1929年,一次空前严重的经济大危机在美国爆发。下列不是经济大危机特点的是( )