{HEAD ~ These ring compounds} are maintained in {TAIL ~ a concentration} of between 0.01 and 4.0 grams per liter of solution in the bath 
are maintained in
{ HEAD ~ These ring compounds } are maintained in { TAIL ~ a concentration } of between 0.01 and 4.0 grams per liter of solution in the bath
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH