简述布尔算符（OR）的作用。

府兵制在初期为兵农合一，但逐步有向兵农分离的趋势。（）

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.

When loading or discharging dry mud or cement，crew members should use goggles and（）.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

我国历史上第一部编年通史著作是（）

府兵制最早创立于哪个时期（）

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。