如图,在圆内接四边形ABCD中,∠C=110°,则∠BOD的度数为( )
A:140°
B:70°
C:80°
D:60°
下表为某饮水机铭牌的部分参数,其内部简化电路如图所示.当S闭合,S1断开时,饮水机处于保温状态,当S、S1同时闭合时,饮水机处于加热状态.求:C水=4.2×l03J/kg•℃
额定电压
220V
额定功率
加热
1000W
保温
44W
热水器的容量
2L
若两条抛物线的顶点相同,则称它们为“友好抛物线”,已知抛物线C1:y1=﹣x2+ax+b与抛物线C2:y2=2x2+4x+6为“友好抛物线”,抛物线C1与x轴交于点A、C,与y轴交于点B.
Lisa was so_________ that she made many spelling mistakes in her homework.