{HEAD ~ Conductor} 50 can be composed of copper, silver, or {TAIL ~ silver plated copper} 
composed of
{ HEAD ~ Conductor } 50 can be composed of copper , silver , or { TAIL ~ silver plated copper }
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL