说明委内瑞拉建设农业浇灌系统的自然原因。

描述南疆、北疆绿洲农业空间分布的形态特征并说明其自然原因。

比较农业生态系统与自然生态系统的异同点。

农业生态系统的营养变化比自然生态系统（）。

深入推进“（）”，扩大农业物联网示范应用。推进重要农产品全产业链大数据建设，加强国家数字农业农村系统建设。

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。