—Is this ______ eraser?
—Yes, it's his eraser. [ ]
A. my
B. his
C. her
D. your
答案:B
活塞式压缩机活塞杆磨损达到0.3mm或活塞杆有划伤应进行()。
A.修理
B.更换
C.调整
D.报废
如图所示的电路中, U="120" V, 滑动变阻器R2的最大值为 200Ω, R1=100Ω.当滑片P滑至R2的中点时,a、b两端的电压为( )
A.60 V
B.40 V
C.80 V
D.120 V