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 （）.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

尺寸线与尺寸界限（）相互垂直。

机械制图规定：设计时给定的尺寸称基本尺寸。（）

机械制图规定：最大极限尺寸减基本尺寸所得的代数差，称（）

机械制图规定设计时给定的尺寸称实际尺寸。

机械制图中的（）表示尺寸界线和尺寸线。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。