For any piston ring to operate smoothly without scuffing, the ring must be_______.
A: of a material harder than the cylinder line
B: properly lubricated
C: prevented from compressing
D: prevented from rotating during engine operation
A: of a material harder than the cylinder line
B: properly lubricated
C: prevented from compressing
D: prevented from rotating during engine operation
举一反三
- A diesel engine piston ring face is in direct contact with the （）.
- For one or two types of engine， the piston and rod can be withdrawn downwards from the cylinder into the crankcase and then out through the （）.
- I was prevented from (attend)___ the conference.
- What do you imagine ______ him from going A: to prevent B: preventing C: to have prevented D: prevented
- A ring homomophism f from a ring R onto another ring S is an isomophism if and only if kerf=0.( )