{HEAD ~ Treatment} with {TAIL ~ the mild etching compound} may be carried out for about 15 seconds to about 5 minutes, and is usually followed by a water rinse 
with
{ HEAD ~ Treatment } with { TAIL ~ the mild etching compound } may be carried out for about 15 seconds to about 5 minutes , and is usually followed by a water rinse
HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH