可以用来表示岩石抗冻性能指标的是（）。

岩石的抗冻性有不同的表示方法，一般用岩石在抗冻试验前后（）的降低率表示。

属于抗冻岩石的指标，下列正确的是（）。

可以在（）阶段采用Make-or-buy决策分析。

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。

F1系列PLC—OR指令表示（）。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。