南北朝是中国古代数学的蓬勃发展时期。

刘勰字彦和，生活于南北朝时期，是中国历史上著名的文学理论家。他的主要作品有（）

简述魏晋南北朝时期的艺术成就。

新体诗是中国格律诗的萌芽，到唐代进一步发展变化，便形成了“近体诗”（）

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.

魏晋南北朝文学的主要成就是（）。

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。