谷子的产量形成特点是什么？

谷类作物产量形成的主要特点是产量成分的（）。

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

农业技术经济学的基本理论是什么？

农业技术经济学的对象是什么？

农业技术经济学的学科特征是什么？

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.

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。

生态农业必须具备的特点是什么？