单项选择题
A.combustion control air system
B.supply air system
C.ships service air system
D.low pressure deck air system
单项选择题 The sensible heat of air is dependent upon the （）.
单项选择题 Which of the devices listed, when used on an electro-hydraulic steering gear, keeps the movement of the redder closely in step with the steering wheel?（）
单项选择题 Propeller pitch speed minus ship speed divided by the propeller pitch speed is termed （）.