钢结构工程常用的焊接方法有：药皮焊条手工电弧焊、自动（）、气体保护焊。

手工电弧焊，药皮中以（）为主要组成物的焊条称为钛型焊条。

手工电弧焊条药皮的作用是（）。

药皮的作用是保证（ ）获得良好的化学成分和机械性能。并使焊条具有良好的焊接工艺性能。

OR指令的作用是: 。( )

焊条药皮的组成成分较复杂，根据原料的不同作用可分为（）

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.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

焊条药皮的主要作用是（）

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。