单项选择题
A.corrosion fretting B.insufficient lubrication C.abnormal wear D.fatigue failure
Fuel oil day tanks for diesel engines must be checked a...
单项选择题Fuel oil day tanks for diesel engines must be checked and cleaned and cleaned at regular intervals in order to remove（）
A.sludge B.water C.micro-organism growth D.all of the above
Excessively worn, or polished ends on a diesel engine v...
单项选择题Excessively worn, or polished ends on a diesel engine valve spring, indicate（）
A.burned exhaust valves B.excessive spring compression C.spring surge D.worn valve seats
A loud clicking noise from the valve compartment of an ...
单项选择题A loud clicking noise from the valve compartment of an operating diesel engine would indicate（）
A.worn valve seats B.worn main bearing C.excessive valve clearance D.weak rocker arm springs
