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.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

关税同盟理论的提出者是（）

关税同盟理论是由（）提出的

根据关税同盟理论，下列属于关税同盟的静态效应的是（）

系统提出关税同盟理论的经济学家是（）

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。