挖掘机有哪些特点？并分析挖掘机反铲工作方式。

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.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

以下哪些情况会造成提示“Incorrect number or IP address”？（）

釜式反应器的维护要点有哪些？

挖掘机装载时，铲斗可以从汽车司机室上方通过。

F1系列PLC—OR指令表示（）。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

哪些货物运输时托运人必须派人押运？押运人数有何规定？