These piston rings are so badly worn that they must be （）.
A
举一反三
- The piston rings are manufactured with a diameter （） the bore of the cylinder.
- On the factory floor, protective hats and boots_______. A: must be worn B: must worn C: must to be worn
- Among the rings of a piston the （） one is subjected to the greatest load and temperature.
- In western culture, wedding rings are worn on right hand.()
- Either a low injection pressure or a leakage of piston rings is able to lead （）.
内容
- 0
The sealing rings are in four parts and pressed together around the piston rods by means of （）.
- 1
Before replacing a piston you should check the rings to see that all clearances and gaps are （） the permissible tolerances.
- 2
Before replacing a piston you should check the rings to see that all clearances and gaps are within the permissible （）.
- 3
The energy for pushing this piston up can be supplied from （）， so that the piston can keep moving up and down.
- 4
All the rings are slightly rounded on their external top and bottom edges to keep the oil film on the cylinder liner during （） for new piston rings.