A:Only one.
B:Lucy.
C:My aunt.
一个乘数是5,另一个乘数是9,积是( )
如图1,抛物线y=ax2+bx+2与x轴交于A,B两点,与y轴交于点C,AB=4,矩形OBDC的边CD=1,延长DC交抛物线于点E.