单项选择题
When using a fuel with a higher than normal sulfur content in an auxiliary diesel engine, you should（）
A.maintain higher than normal jacket water temperature B.change the lube oil more frequently than normal C.maintain a higher air-box temperature than normal D.maintain a higher air-box pressure than normal
单项选择题 When fuel is injected late into a diesel engine cylinder,（）.
单项选择题 In a diesel engine, when installing new piston rings it is important to check（） Ⅰ.ring gap clearance Ⅱ.side clearance
单项选择题 At bottom dead center, the centerline of the connecting rod usually coincides with the（）
