单项选择题
Which term describes piston pins having bearing surfaces in both the piston bosses and connecting rod eye?（）
A.Stationary B.Full floating C.Semi-floating D.Free rolling
单项选择题 The longer the ignition delay period occurs in a diesel engine, the （）.
单项选择题 Poor combustion in a diesel engine can be caused by （）.
单项选择题 High firing pressures and a low exhaust temperature in a diesel engine may result from （）.
