● In （74） the only element that can be deleted or removed is the one that was inserted most recently.（74）

输出继电器（OR）通过一对（）触点将PLC的控制信号传递给负载。

口服补液及时纠正脱水，应用ORS，说法正确的是（）

当ALE信号有效时，表示（）。

Every deliberate act of wrongdoing by the master or any of the crew against the ship or cargo，without the authorization or privity of the Shipowner or his agent，is（）.

（）, 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.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

8051单片机系统的振荡晶体频率为6MHz，当CPU不访问外部RAM时ALE引脚输出信号的频率是 （）。