To lubricate the swivel or remove corr

1、The removal of （） from lubricating oil

The removal of （） from lubricating oil will reduce engine wear and possible breakdowns.Acontaminating waterBcontaminated additivesCcontaminated fuelDcontaminating impuritie

2、Valve lash, or clearance refers to the

Valve lash, or clearance refers to the （）Aclearance between the top of the valve stem and the rocker armBcompression of the valve springsCclearance between the valve seat inserts and the headDout of roundness of the fuel injection cam

3、When to remove scale from the cooling

When to remove scale from the cooling spaces, acid solution （） in the system can be tested from time to time by putting some on to a piece of lime.AstrengthBdenseCpercentageDvelocity

4、The process to remove exhaust gases by

The process to remove exhaust gases by blowing in fresh air is called （）.AchargingBsuperchargingCstartingDscavenging

5、The ability of lubricating oils to res

The ability of lubricating oils to resist viscosity changes during temperature changes is indicated by the（）AAmerican PetroleumBInstitute number viscosity index numberCSeconds Saybolt Furol numberDSeconds Saybolt Universal number

6、It is necessary to remove （） from the

It is necessary to remove （） from the cooling spaces.AscarBscaleCspurDbilge