5x³-6x²+15x-14=0的有理数根是（）。

发现的第一个无理数是（）

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。

在有理数集合Q上定义的二元运算*：x*y＝x＋y－xy，则Q中满足（　　）。

复杂的周期信号可借助傅里叶级数展开成（），其中任两个分量的频率比都是有理数.

复杂的周期信号可借助傅里叶级数展开成一系列的离散的简谐分量之和，其中任两个分量的（）都是有理数.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。