A:a; a
B:the; the
C:the; 不填
D:不填; the
We have a new____ and a large____ ____ .
如图所示,a、b灯分别标有“3.6V 4.0W”和“3.6V 2.5W”,闭合开关,调节R,能使a、b都正常发光.断开开关后重做实验,则( )