抛物线y=ax2+c与x轴交于A,B两点,顶点C,点P为抛物线上一点,且位于x轴下方. (1)如图1,若P(1,﹣3),B(4,0).D是抛物线上一点,满足∠DPO=∠POB,且D与B分布位于直线OP的两侧,求点C与点D的坐标; (2)如图2,A,B是抛物线y=ax2+c与x轴的两个交点,直线PA,PB与y轴分别交于E,F两点,当点P在x轴下方的抛物线上运动时,是否为定值?若是,试求出该定值;若不是,请说明理由(记OA=OB=t) After three months of hard work, I’d like to
travel in a nice small town, especially ________ with an ocean view.
A. one B.
that C.
the one D.
this