单项选择题
If the compression ratio is increased on any diesel engine, （）
A.the expansion ratio will decrease B.combustion will be slowed down C.thermal efficiency will decrease D.thermal efficiency will increase
单项选择题 If a used lube oil analysis indicates excessive fuel dilution, the lube oil should be （）
单项选择题 How are the pressure and temperature affected in a diesel engine cylinder during compression?（）
单项选择题 A diesel engine is warmed up and white vapor is in the exhaust，this could indicate （）
