Cooling of engine is achieved by circulation a cooling liquid around internal passages within the （）.

[单选题]The cooling water of the diesel engine should be treated with chemical, because it contains .A．alkaliB．acidityC．salinityD．impurity

[单选题]Improper cooling of a diesel engine cylinder liner due to the accumulation of scale deposits may cause （）.A . low compression pressureB . increased piston wearC . increased cylinder lube oil consumptionD . poor contact between compression rings and l

[单选题]In a diesel engine cooling water system, a pH of 60 indicates a/an （）.A . slightly acidic conditionB . slightly alkaline conditionC . overtreatment of waterD . neutral condition of water

[单选题]For diesel engine piston cooling, lubricating oil can be supplied to the pistons by a/an （）.A . oil sprayB . oil bathC . oil control ringsD . drilled passage through the camshaft

[单选题]A diesel engine cooling water system with a pH factor of 30 indicates a condition of （）.A . slight acidityB . slight alkalinityC . excessive alkalinityD . excessive acidity

[单选题]High diesel engine cooling water temperatures can be caused by （）.A . a worn water pumpB . not enough coolantC . air in the cooling systemD . all of the above

[单选题]Sealing in pump shaft is achieved by means of the ( ).A．gasketB．packingC．o-ring

[单选题]She [achieved]success with diligence.A.reachedB.reapedC.attainedD.took

[单选题]She [achieved]success with diligence.A.reachedB.reapedC.attainedD.took

[单选题]As to the piston cooling, of the following, which statement is not true?（）A . Because the piston is exposed to very high temperature, it must be cooledB . The lower the piston cooling temperature is, the better it isC . Both water and lube oil can be