{HEAD ~ The devices} comprise {TAIL ~ a body} formed of a polymeric backbone having a repeating unit of a hydrocarbon radical and symmetrical dioxycarbon unit with a multiplicity of organic groups bonded thereto 
comprise
{ HEAD ~ The devices } comprise { TAIL ~ a body } formed of a polymeric backbone having a repeating unit of a hydrocarbon radical and symmetrical dioxycarbon unit with a multiplicity of organic groups bonded thereto
HEAD HEAD HEAD HEAD HEAD HEAD REL 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 OTH OTH OTH OTH