In the process of the stand-by, warm-up the engine usually through give preheat of which parts of the diesel engine?（）

单项选择题The main purpose of warming the parts of the main engine is （）

A.to reduce heat stress
B.to reduce low temperature corrosion
C.to improve firing and starting performance
D.fuel saving

单项选择题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

单项选择题The purpose of engine stand-by is that （）

A.the main engine in the stand-by condition
B.auxiliary machinery in the stand-by condition
C.dynamical equipments in the stand-by condition and could be used immediately
D.A and B

单项选择题Which is false about engine trials?（）

A.engine trails should be done after finishing the operation of turning the engine with the turning gear and starting the engine on air briefly
B.in the operation of engine trails, the main engine should be running in low-speed
C.As to the ship equipment with twin main engine, engine trials should be done with one engine ahead and another engine astern at the same time
D.the order “engine trials” should be given by the bridge

单项选择题Which of the following is false?（）

A.preparation for stand-by should be organized by engine room
B.engine trails should be agreed with bridge, and then do it
C.As to engine trials of the twin diesels and two propellers, the two diesels should use “slow ahead” at the same time
D.After engine trials, the handle of the engine telegraph should be put in the “stop” position