【简答题】A.He thinks David is not reliable. B.He's willing to trust David. C.He has told his doubts to David. D.He thinks David will benefit from this experience.
【单选题】As reliable parents, they never ______ to give their son what he is promised.
【单选题】直流电机 磁场对气隙磁场的影响,称为电枢反应。
【单选题】下列关于电枢反应说法错误的是( )。
A.
使气隙磁场发生畸变,物理中性线偏离几何中性线;
B.
考虑饱和时,每极磁通略有减小,即具有一定的去磁作用。
C.
直流电机负载时,电枢磁场对主磁极的磁场影响称为电枢反应。
D.
由于电枢反应的影响,对于电动机,物理中性线将顺着电枢旋转方向从几何中性线向前移过一定的角度α。
【单选题】—John is very ______ . —if he promises to do something he’ll do it.
【简答题】直流电机 磁场对气隙磁场的影响,称为电枢反应。
【单选题】He had the 'right' accent, ______ middle - class parents in court, reliable witnesses, and he could obviously afford a very good solicitor.
【单选题】John is very ——if he promises to do something he’ll do it .
【简答题】直流电机负载运行时,电枢绕组中有电流通过,也产生磁通势,此磁通势影响励磁磁通势产生的磁场,有可能改变气隙磁密分布情况及每极磁通量的大小,这种现象称为____。