大多数航空活塞发动机采用的冷却方式是（）.A.液冷式 B.气冷式 C.滑油系统哦冷却

(2013·四川省六校二模)Jack is an outgoing child, usually kind and helpful, but he ________ lose temper sometimes.

A．must

B．would

C．can

D．should

简述小麦研磨系统？

计算机病毒具有( )的特点。

A．传播性和破坏性

B．偶然性

C．隐蔽性

D．潜伏性和感染性

巴师夏“经济和谐论”的经济学依据是（）。

A.服务交换论

B.效用价值论

C.节欲论

D.生产费用价值论

Which signal is detected as originating from a SART?（）

A.The Morse code distress series S-O-S repeated 3 times followed by DE and the vessel's call sign

B.A line of blip code on a radar screen outward from the SART's position along its line of bearing

C.A line of blip code on a radar screen inward from the SART's position to its own ship along its line of bearing

D.None of these