石油主要是由（）、（）、氮、氧、硫及其它微量元素等元素组成的。

（）是一切生命的基础，它是由碳、氢、氧、氮硫及磷等元素组成的。

根据煤中全硫及煤灰中的硫含量，可计算出煤中不可燃硫及可燃硫含量。

以化合物形态存在的元素叫做元素的（）。

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。

下列哪种肥料元素在土壤中移动性强。（）

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。