按照煤层的厚度将煤层分为（）、中厚煤层、厚煤层、煤线。

煤层倾角大于30°的煤层为急倾斜煤层。（）

地下开采的煤层按倾角可以划分为近水平煤层、缓倾斜煤层、倾斜煤层、急倾斜煤层、其中急倾斜煤层的倾角大小为（）。

地下开采的煤层按倾角可以划分为近水平煤层、缓倾斜煤层、倾斜煤层、急倾斜煤层、其中缓倾斜煤层的倾角大小为（）。

地下开采煤层中，属倾斜煤层的煤层倾角为（）.

地下开采煤层中，属近水平煤层的煤层倾角为（）.

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。

露天煤矿通常按煤层分为哪三类？按煤层倾角分哪四类？

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。