Sliding friction between the _________ of the cam and the cam follower is considerable.
A: inside
B: front
C: surface
D: back
A: inside
B: front
C: surface
D: back
举一反三
- When the follower is on the base circle of the cam， the pump plunger is at the （） of its stroke.
- retro-______ A: below B: front C: inside D: back
- When the cam is rotated or turned, the follower would be moved either right or left, or .
- The teaching building is ____ the library. A: A. inside B: B. back C: C. in the front of D: D. in front of
- （）no friction between the surface of the road and our feet, we could not walk at all. A: If there was B: Were there C: Was there D: There was