On most modern diesel engines, the main and connecting rod bearings receive their lubricating oil by （）.

A.stiffen the bedplate in way of the main bearings to increase the engines longitudinal strength
B.accept most of the tensile loading that results from the firing forces developed during operation
C.mount the engine frame securely to the hull to prevent shaft coupling misalignment
D.connect the crosshead solidly to the piston rod

A.cam followers
B.push rods
C.combustion gases
D.valve springs

A.cylinder head water outlet header
B.cylinder jacket inlet main
C.heat exchanger inlet connection
D.jacket water pump suction line