（）, 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.

When loading or discharging dry mud or cement，crew members should use goggles and（）.

Effects which are dutiable or subject to prohibitions or restrictions should be declared in （）.

（）are liable to be stoten, pilfered or may damaged due to improper handing or stowage.

碳元素对钢材的性能有哪些影响？

简述化学元素对钢材性能有哪些影响？

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

钢材中碳元素含量提高对钢材性能的影响是（）

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。