单项选择题
A.avoid using liquid-cooled nozzles whenever possible
B.avoid low cooling water temperatures
C.avoid prolonged overloading of the engine
D.make certain the gasket seal between the nozzle and cylinder head is tight
单项选择题 In a simple mechanical governor, the （）
单项选择题 If a diesel engines exhaust temperature is abnormally high, the cause could be（）
单项选择题 The knock occurring when a cold diesel engine is started and continues while running at low speed, but stops when the engine reaches normal operating speed and temperature, is（）.