单项选择题
A diesel engine is operating with excessively high exhaust temperatures at all cylindersTo correct this condition, you should FIRST （）.
A.reduce the engine load B.increase the cooling water flow C.increase the lube oil pressure D.adjust the fuel rack
单项选择题 The function of diesel engine piston compression rings is to （）.
单项选择题 A diesel engine piston ring face is in direct contact with the （）.
单项选择题 If the water level dropped rapidly in the expansion tank of a closed diesel engine cooling water system, you should suspect a （）.
