380V/220V的三相四线式中性点接地系统属于（）。

该单位工程的临时供电工程专用的电源中性点直接接地的220/380V三相四线制低压电力系统，必须符合( )的规定。

三相四线380/220V低压供电系统中采用中性点直接接地、引出N线或PEN线。（）

三相四线380/220V低压供电系统、电气设备的外露导电部分与系统的保护线连接的系统称（）系统。

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.

The （） is used for hauling in or letting out the wires or ropes.

Vessels must be（）valid certificate of nationality or certificated of registry or license.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

供电企业供电的额定电压为：高压供电（）、35（63）、110、220千伏；低压供电：单相220伏、三相380伏。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。