Fires occurring in combustible metals,

1、To avoid scavenge fires occurring the

To avoid scavenge fires occurring the engine timing and equipment maintenance （）.Ashould be correctly carried outBshould correctly be taken placeCshould carded with careDmust to carry out with great care

2、Combustion knock can occur in the cyli

Combustion knock can occur in the cylinders of a diesel engine under any condition permitting （）.Aa shortened ignition delay periodBa lean fuel/air mixtureCexcess fuel in the combustion chamberDrapid vaporization of injected fuel droplet

3、Fires involving combustible metals are

Fires involving combustible metals are classified as （）.Aclass "A" firesBclass "B" firesCclass "C" firesDclass "D" fire

4、To avoid scavenge fires occurring the

To avoid scavenge fires occurring the engine timing and equipment maintenance （）.Ashould be correctly carried outBshould correctly be taken placeCshould carried with careDmust to carry out with great care

5、Fires in escaping flammable gas are qu

Fires in escaping flammable gas are quickly brought under control by（）Astopping the flow of gasBreducing the chemical chain reactionCincreasing the oxygen supplyDcooling below the autoignition point

6、Theoretical perfect combustion in a di

Theoretical perfect combustion in a diesel engine yields by-products of （）.Aaldehydes and carbon dioxideBwater vapor and carbon monoxideCnitrogen and carbon monoxideDwater vapor and carbon dioxide