单项选择题
A.check the air filter for dirt
B.check for an exhaust leak
C.check the cooling water temperature
D.notify the bridge that you are going to shut the engine down
单项选择题 Operating a diesel engine under light loads and at low temperatures for an exhaust for an extended period can result in（）
单项选择题 In a turbocharged four-stroke/cycle diesel engine, the exhaust valve remains open until after top dead center and the intake valve opens before top dead center to（）.
单项选择题 Early injection timing is indicated by （）.