儿童的思维运算已具有可逆性和守恒性，但思维运算还离不开具体事物的支持，说明儿童的认知发展所处的阶段是（）。

写出以下运算符代表信义：AND（），OR（）。

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

假定用x代表二进制数1010B，用y代表二进制0110B，若x与y通过逻辑运算后得到的结果是1100B，则以下选项中能实现这一逻辑运算功能的算式是（）。（提示：AND代表逻辑乘，OR代表逻辑加，NOT x代表对x逻辑取反）

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。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

布尔逻辑具体检索时，是通过三个布尔运算符来实现其功能的：AND、OR、（）。