（）, 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（）.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

吊装作业应有专人负责、统一指挥，各个临时拉线应设专人松紧，各个（）应有专人看护。

大型机械作业或多机配合作业时，不需要设专人统一协调指挥。

在线路上使用小型养路机械作业时，应由（）担任施工负责人。

在线路上使用小型养路机械作业时应注意什么？

在线路上使用小型养路机械作业时，应由（）担任施工负责人。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。