单项选择题
A.low firing pressure and low exhaust temperatures
B.low firing pressure and normal exhaust temperatures
C.high firing pressure and low exhaust temperatures
D.high firing pressure and high exhaust temperatures
单项选择题 The closing of the exhaust valves used on a modern, large, low-speed, main propulsion diesel engine may be directly provided by （）.
单项选择题 The water in an operating auxiliary boiler should be tested for alkalinity and chloride content each（）.
单项选择题 On a turbo-charged, medium-speed diesel engine, which of the following problems is an indication of a restricted air intake passage?（）