受拉螺栓的强度计算中，只计算螺杆的拉伸强度，而不计算螺纹牙、钉头的剪切强度，这是因为（）。

螺栓的强度计算是以螺纹的（）来计算的。

已知X=21，Y=15，Z=22，计算表达式（（X>Y）or（Y>Z））and（（X<><>

螺栓球节点应按设计指定的规格的球的最大螺栓孔螺纹进行抗拉强度保证荷载试验，当达到螺栓的（）倍设计承载力时，螺孔、螺纹及封板仍完好无损为合格。

直齿锥齿轮传动的强度计算方法是以 （）的当量圆柱齿轮为计算基础。

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。