A sudden decrease in the diesel engine lube oil viscosity could be an indication of（）

A.erosion and cratering of the nozzle orifices
B.fuel leakage into the nozzle drain line
C.fuel leakage before and after injection
D.insufficient fuel delivery though that nozzle

A.check cylinder lubrication
B.connect the pressure indicator pressure
C.test cylinder heads
D.connect the exhaust gas pyrometers

A.At zero load the intake manifold pressure is greater than the exhaust manifold pressure
B.At full load the intake manifold pressure and exhaust manifold pressure are equal
C.At full load the intake manifold pressure is less than the exhaust manifold pressure
D.At full load the intake manifold pressure is greater than the exhaust manifold pressure