风光互补路灯(如图)依靠风力和太阳光发电来提供电能,其尾翼使风轮能绕竖直轴在水平面内自动转向风来的方向.下列有关分析错误的是
A:风力发电利用了电磁感应现象
B:太阳能发电是将太阳能转化成电能
C:尾翼的主要作用是平衡风轮
D:与传统路灯相比,该路灯更节能环保
二次函数y=ax2+bx+c的图象如图所示,下列结论错误的是( )
— There's somebody at the door. Who ____ it be? Is it the postman?—No. It ______ be him. It's just seven o'clock. It's too early.