The main purpose of starting the diesel engine on air briefly is .A.to inspect if the cyli

The main purpose of starting the diesel engine on air briefly is .

A.to inspect if the cylinder has the water leakage

B.to expel out the residual water /gas /oil from the cylinder

C.to check if fuel supply is normal

D.A and B

请帮忙给出正确答案和分析，谢谢！