如图,在平面直角坐标系中,抛物线y=ax2+bx+c的顶点坐标为(2,9),与y轴交于点A(0,5),与x轴交于点E、B.
当神经细胞膜两侧的电位表现为内负外正时,此电位称()
Daming ____ (go) to the Great Wall last weekend.