什么什么是基本顶初次来压、初次来压步距与周期来压？

从开切眼煤壁到老顶初次来压时与工作面切顶线的距离叫什么？

系统中雷达状态包括Unknown、Operational（or ON）、Failed（or OFF）、Detached。

Shutdown price（or point，or rule） 停业价格（或停业点、停业原则）

翻译：With Average or With Particular Average（WA or WPA）（）

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。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

随着工作面不断推进。基本顶（又称老顶）周而复始地发生断裂的现象，称为基本顶初次来压。（）

采煤工作面矿山压力显现的主要影响因素是推进速度。