单项选择题
A.Electric power and starting air
B.Lube oil standby pump and control air
C.Hydraulic switch and engage jacking gear
D.Motor drain and pneumatic control system power
单项选择题 A diesel engine experiences a sudden loss in speed, accompanied by black exhaust smoke, with the fuel rack at maximum, and speed remaining below normal the probable（）
单项选择题 Which of the following problems can occur if you continually fail to drain off condensate from a starting air receiver?（）
单项选择题 During the valve overlap period, the exhaust pressure of a turbochargers, four-stroke/cycle diesel engine must be less than the intake manifold pressure to ensure （）