As such, the main body 12, by itself, is essentially {TAIL ~ a conduit} through which {HEAD ~ material} may pass 
through pass
As such , the main body 12 , by itself , is essentially { TAIL ~ a conduit } through which { HEAD ~ material } may pass
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL REL OTH HEAD HEAD HEAD HEAD HEAD OTH REL