从生物学意义上说，（）是作为人区别于动物的一个重要标志。

实验动物学是进行动物实验和研究实验动物的一门科学。

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。

世界上最早的玩具相传是亚当娃娃和夏娃娃娃。

娃娃鱼是世界上（）.

在动物分类中，娃娃鱼属于（）。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。