The cooling of the piston is carried out by circulating （） across the underside of the crown and inside the ring belt or through specially shaped passages.

A.jacket water
B.make-up water
C.boiler water
D.flushing water

A.the faster it will evaporate
B.the slower it will condense
C.the slower it will evaporate
D.the faster it will flow

A.connecting rod
B.piston rod
C.bearing housing
D.none of the above