恒定流时流线的形状将不随时间变化。

流线是拉格朗日法分析流体运动的概念,迹线是欧拉法分析流体运动的概念。( )

圆管直径为d时,圆管满流时的水力半径为 ___。

非恒定流动中,流线与迹线:( )

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.

恒定流时流线与迹线（）。

恒定流时，液体的迹线与流线重合。而非恒定流时，迹线与流线一般不重合。（）

非恒定流，以下对于流线和迹线的正确说法是（）。

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。