如图所示,两只白炽灯泡L1和L2与电源、电键组成的电路中,当电键闭合后,发现电压表V1、V2的示数相同,且电流表A的示数为零,则可能发生的故障是( )
A:L1断路
B:L2断路
C:L1短路
D:L2短路
根据短文,选择正确答案。
Van and Ted are twin brothers. They look the same. They are English. They are eleven. They are in No.15 Middle School. They are new students in Class One, Grade One. Van sits in Row One. Ted sits in Row Three.
通车十年,青藏铁路有效降低了交通运输成本,对加快西藏经济社会发展、推动经济转型升级、打造旅游升级版、促进农牧民增收致富、建设美丽西藏、增进民族团结和巩固祖国边防作出了不可替代的贡献。新时期,建设美丽西藏,共圆祖国梦想,需要( )
若fx为奇函数且在0,+∞上递增,又f2=0,则fx-f-xx>0的解集是( )