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 （）.

The（）may examine or re-examine the goods or take samples from them straightaway in the absence of the consignee or the consignor whenever it considers this necessary.

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

Banks have no liability for any delay or loss caused by postal or telex failure.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

选择断面形状的依据是什么？

简述巷道断面形状的选择依据。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。