（）, 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（）.

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。

PLC的输入控制开关可以是（）、继电器和接触器的触点等。

PLC控制系统和继电器控制系统相类似，也是由输入、逻辑控制和（）三部分组成。

F1系列PLC—OR指令表示（）。

FX2N 系列可编程序控制器输入常开点用( )指令。 A、LD B、LDI C、OR D、ORI

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。