什么叫滤料"有效粒径"和"不均匀系数"？"不均匀系数"过大对过波、和反冲洗有何影响？

什么叫不均匀沉降？减少不均匀沉降可采取哪些措施？

什么叫均匀分布？什么叫均匀流段？

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。

（）应当落实农田水利工程运行维护经费，保障运行维护工作正常进行。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

什么是农田排水的任务？农田排水的目的是什么？