In a diesel engine, when installing new piston rings it is important to check（）
Ⅰ.ring gap clearance
Ⅱ.side clearance

A.angularity of the piston motion
B.inertia moment from the piston
C.centerline of the cylinder
D.centerline of the king pin

A.Worn intake valve guides
B.Pitted pre-combustion chambers
C.Loose valve tappets
D.High exhaust back pressure

A.fuel knock
B.increased power
C.low compression pressure
D.high exhaust temperature