单项选择题
Low compression pressure in a diesel engine may be the result of （）
A.insufficient fuel supply due to fuel pump valves sticking or leaking B.excessive mechanical clearance between the piston crown and cylinder head C.excessively worn fuel pump plunger D.excessive exhaust back pressure
单项选择题 Exhaust gas pyrometers are useful for（）
单项选择题 A connecting rod in a four-stroke/cycle diesel engine is subject to（）
单项选择题 Thermocouple pyrometers are used on large, main propulsion diesel engines to indicate the temperature of the（）
