（）, 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.

弹簧式安全阀主要依靠弹簧的作用力来达到密封

非镀锌电缆桥架间连接板的两端跨接铜芯地线，接地线最小允许截面积不小于（）mm²，镀锌电缆桥架间连接板的两端不跨接接地线，但连接板两端不少于（）个有防松螺帽或防松垫圈的连接固定螺栓。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

弹簧是依靠（）而做功的常用机械零件。

弹簧垫圈常用于经常拆卸的螺纹连接的防松。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

在螺栓连接中，采用弹簧垫圈防松的是（）

利用螺栓连接母线的要领是：拧紧螺母、使弹簧垫圈（）。