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。

智能结构即（）的综合反映。?

概念结构设计的目标是产生DB概念结构(即概念模式)，这种结构主要反映

概念结构设计的目标是产生DB概念结构(即概念模式)，这结构主要反映

概念结构设计的目标是产生数据库概念结构(即概念模式)，这结构主要反映( )

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。