简述中国史学史的分期标准。

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

简述布尔算符（OR）的作用。

简述五四运动的历史特点和历史意义。

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。

请简述宋代绘画的兴盛及其特点。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。