*____ of different thickness are inserted between the shells to enable adjustment of the bearing clearances.
举一反三
- Shims of different thicknesses are inserted between the shells to enable adjustment of （）.
- The shells are secured by means of bearing caps and studs， the necessary clearance being provided by means of （） of different thickness.
- A distance piece， with ground faces， may be interposed between the rod and the bearing housing， its thickness being chosen to ensure the correct （）.
- A main bearing consists of two shells which are secured by means of studs and （）.
- The main bearing shells are made of steel with a lining of bearing metal which may be white metal， copper-lead or aluminum-tin alloy What is the meaning of “which” in the sentence above?（）