单项选择题 “lover-leafing”is a term used to describe corrosive wear at several separate points around liner circumference- iein some cases the liner bore may assume a “clover-leaf”shape（）

单项选择题 If the gas pressure behind the ring is built up too slowly, and thereby exerts an inadequate outward pressureIn such a case, the combustion gas can penetrate between the liner and ring, and violently force the ring inwards, in the grooveWhat result will this type of sudden "shock" loading eventually lead to?（）

单项选择题 Broken piston rings manifest themselves during the scavenge port inspection by（）