The lowest ring of a piston is (). A.a coi
题型:单项选择题
问题:
The lowest ring of a piston is ().
A.a coil spring
B.a sealing ring
C.an oil distributor ring
D.main seal ring
The lowest ring of a piston is ().
A.a coil spring
B.a sealing ring
C.an oil distributor ring
D.main seal ring