A:①→②→③→④
B:④→②→①→③
C:③→④→①→②
D:③→①→④→②
己知抛物线方程为y2=2pxp>0,焦点为F,O是坐标原点,A是抛物线上的一点,FA→与x轴正方向的夹角为60°,若△OAF的面积为3,则p的值为( )
Legend has it that the origin of the Dragon Boat Festival is to the soul of Qu Yuan.
下列政权中,曾一度统一黄河流域的是( )
①曹魏 ②西晋 ③前秦 ④北魏 ⑤东晋