根据空气动力学直径，粉尘可分为（　　）。

什么是空气动力系数？

园艺上常根据什么原理进行果树整枝修建？

自动空气开关能对电气或电气设备起（）；（）；（）；（）；（）；（）作用

根据工程经济分析比较原理，对两个以上的工程项目进行经济效益比较时，为什么要强调可比原则，必须遵循哪些原则？

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。

热泵机组根据什么原理进行采热？

空气能根据什么原理进行采热？

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。