交流伺服电机的旋转方向可以个感应电动机一样通过改变三相相序来改变。（）

在三相电路中，对于任意一组不对称的三相相量，可以分解为三组三相对称的相量，称为相序分解。又称对称分量法。

对称三相系统中的各相相位相差多少？

Every deliberate act of wrongdoing by the master or any of the crew against the ship or cargo，without the authorization or privity of the Shipowner or his agent，is（）.

（）, or drum is used for hauling in or letting out the wires or ropes which will fasten the ship to the shore.

A salvor may be（）the whole or part of the payment due under Salvage Convention to the extent that the salvage operations have become necessary or more difficult because of fault or neglect on his part or if the salvor has been guilty of fraud or other dishonest conduct.

对称三相电路中，三相相量的相位角之差（）。

两相相短路接地时的复合序网是在短路点处是如何连接的？

电力系统两相相间短路的复合序网是（）。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

系统发生两相相间短路时，短路电流包含（）分量。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。