环操作，必须是同一个系统，操作前应考虑合环点两侧的相角差和电压差，电压相角差一般不超过（），电压差一般不得超过（）

差保护每次投入前，应检查两侧差流及相角，差流一般应小于（）mA，相角一般应小于（）

电压互感器相角差

若控制系统的频率特性在截止频率附近有相角迟后，可利用（　　）补偿相角滞后，用来提高系统的相位稳定裕量，改善系统的动态特性。

若控制系统的频率特性在截止频率附近有相角迟后，可利用（　　）补偿相角迟后，用来提高系统的相位稳定裕量，改善系统的动态特性。

三相交流电的三相电流初相角依次相差（）。

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.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。