空气充填泵传动带(V belt)磨损时,应()。
A、更换传动带
B、检查保险丝
C、增加润滑油
D、更换安全阀
参考答案:A
如图所示,电源电压6V不变,电阻R1=10Ω,R2=20Ω,当开关S接到点2时,电压表示数为 V;当开关S转换到点1时,在10s内电流所做的功为 J.
The ancient Jewish people regarded themselves as the salt of the earth , the chosen few by God to rule the world.
A.outcast
B.elite
C.nomad
D.disciple