什么是理想液体？为什么要引入理想液体的概念？

理想液体与实际液体的主要差别在于：（）

理想液体就是不考虑黏滞性的实际不存在的理想化的液体。（）

（2006）理想液体与实际液体的主要差别在于：（）

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。

对于不可压缩液体恒定总流，断面平均流速与过水断面积（）。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。