在纯电感电路和纯电容电路中,有功功率都为()。
A、零
B、非零
C、大于零
D、小于零
参考答案:A
It is required by the rules that students______ get grades not lower than 85%in any subject in
order to get the scholarship. [ ]
A. will
B. may
C. shall
D. would
对顶轴油泵叙述正确的有()。
A、汽机转速小于1200rpm时,联启投备泵;
B、顶轴油泵出口母管压力低于12MPa,联启备用泵(联锁投入);
C、联锁投入,汽机转速大于1200rpm时,联停顶轴油泵;
D、联锁投入,入口油压低于0.048MPa时,联停顶轴油泵。