After etching, {HEAD ~ the workpieces} are washed with {TAIL ~ a mainly neutral washing liquid} consisting of a solution of the salt required for regeneration of the etching agent 
After etching , { HEAD ~ the workpieces } are washed with { TAIL ~ a mainly neutral washing liquid } consisting of a solution of the salt required for regeneration of the etching agent
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH