A:①②
B:①②③
C:①③④
D:②④
|﹣3|的相反数是
⑴Where's your mum?
⑵Am I going to have a party?
⑶The balloon is flying away.
⑷The teacher can help me.
start:____ duck:____ soon:____
stay:____ mess:____
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.