二次函数y=ax²+bx的图象如图，若一元二次方程ax²+bx+m=0有实数根，求m的最大值．

选择适当的选项补全对话。

A. Is he friendly? B. Yes, you're right. C. A boy or a girl? D. Who's he? E. No. He has glasses and his shoes are blue.

John: Hello, Sarah! I have a new friend.
Sarah: ____
John: A boy.
Sarah: ____
John: He is tall and thin. He has short hair.
Sarah: ____
John: Yes, and he is nice, too.
Sarah: Is he Mike?
John: ____
Sarah: I know. He is Peter. He is near the door.
John: ____

相传，下图中的人物建造宫室，制作衣裳，发明弓箭和指南车，他是（    ）

如图，用细线系一小球，使它在水平面内做匀速圆周运动，在运动过程中：（       ）

如图是一个正六棱柱，它的俯视图是（   ）