由于Maillard反应的开始步骤是胺与羰基的亲核加成反应，因此，酸性条件（）反应的进行；当pH小于3时可以有效地（）反应的进行。

吡啶和强的亲核试剂作用时发生什么反应？（）

为什么羧酸衍生物的亲核取代反应活性为：酰卤>酸酐>酯>酰胺？

简述布尔算符（OR）的作用。

OR指令的作用是: 。( )

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。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。