When good and steady service conditions have been achieved, the running surfaces of the piWhengoodandsteadyserviceconditionshavebeenachieved,therunningsurfacesofthepistonringsandcylinderlinerwillbe_____Inaddition,theringswillmovefreelyinthegroovesandalsobewelloiledintact,andnotundulyworn、 A、hazylight B、hazylightbrown C、hazylightblue D、hazylightgrey