A:but
B:and
C:or
如图所示,小灯泡规格为“5V 2.5W”(灯丝电阻的变化不计),闭合开关,当滑动变阻器的滑片移至a端时,电流表的示数为0.5A;当滑片移至b端时,电压表的示数为3V,则( )
关于指南针和磁场,下列说法正确的是( )
用手捏心脏,壁最厚的腔是( )
— is it from your home to your school?
— It is about twenty minutes by bike.