单项选择题
Heat damage to fuel injection nozzles on small high-speed diesel engines, can be prevented by（）
A.employing fuel oil as a cooling medium B.preventing hard carbon deposit on nozzle tips C.avoiding fuel oil temperature exceeding builder’s specification D.ensuring good metallic contact between nozzles and cylinder heads
单项选择题 One of the advantages in the use of a dry liner over a wet liner is（）
单项选择题 One characteristic of a pulse type turbo-charging system is（）
单项选择题 One advantage of dry cylinder liners used in a diesel engine is the（）
