Which of the devices listed is installed on a diesel engine to isolate some of the crankshaft vibrations caused by rotational and reciprocating forces?（）

A.increase the density of the cylinder air charge
B.prevent turbocharger overheating
C.liminate the need for a pre-cooler
D.remove moisture from air compressed by the turbocharger

A.induce carbon formation on cylinder walls
B.improve fuel penetration in the combustion space
C.form a friction reducing film between mating surfaces
D.lubricate the fuel injection

A.Improper fuel rack positioning
B.Lengthy opening of the exhaust valve
C.Excessively early injection timing
D.Extended light load operation