Furthermore, {HEAD ~ the base} may be a metal base and have {TAIL ~ an integrally formed hollow portion} 
have
Furthermore , { HEAD ~ the base } may be a metal base and have { TAIL ~ an integrally formed hollow portion }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL