In an ordinary diesel engine the fuel injection begins （）

[单选题]On a diesel engine, fuel is delivered into the combustion space by （）.A . a cooling systemB . a lubrication oil systemC . an electric systemD . an injection system

[单选题]If the diesel engine fuel injection timing is changed to delay the start of injection until the pistons are at top dead center, the engine will_________.A．backfire through the air intakesB．develop less power under loadC．have high firing pressuresD．li

[单选题]Fuel is admitted to a diesel engine cylinder through the （）.A . intake valvesB . carburetorC . exhaust portsD . injector nozzle

[单选题]The fuel oil system for a diesel engine can be considered in two parts--the fuel supply and the （） systems.A . fuel treatmentB . fuel combustionC . fuel injectionD . fuel separating

[单选题]In a diesel engine, fuel must be broken up into a spray of fine droplets to （）.A . increase its qualityB . obtain complete burningC . reduce its weightD . all of the above

[单选题]For an ordinary four-stroke diesel engine the exhaust valves close （）.A . after TDCB . before TDCC . after BDCD . before BDC

[单选题]For an ordinary four-stroke engine the inlet valves open （）A . after TDCB . before TDCC . after BDCD . before BDC

[单选题]In an ordinary four-stroke engine the exhaust valves open （）A . after TDCB . before TDCC . after BDCD . before BDC

[单选题]For an ordinary four-stroke engine the exhaust valves open （）.A . after TDCB . before TDCC . after BDCD . before BDC

[单选题]_____ the engines, the diesel engine is ____ used engine on boardA．Between / more commonlyB．Among / the most commonlyC．Between / not more commonlyD．Among / not the most commonly