如图所示的电路中,闭合开关,电流表测量的是()
A:通过灯Ll的电流
B:通过灯L2的电流
C:通过灯L1和灯L2的电流之和
D:电源供给电路的总电流
A single-parent child should have the right to enjoy normal parental love from both just as his other peers, which some psychologists see as _____to their emotional well-being.
“人有多大胆,地有多大产”这句话反映的是哪一历史事件( )
某同学探究金属单质的活动性时发现X、Y都能跟稀硫酸反应,而Z不能;Y能在X的盐溶液中置换出X.则它们的金属活动性顺序为( )