{HEAD ~ An amount} of {TAIL ~ exhaust} coming out of each opening 48 may be the same or may be different 
of
{ HEAD ~ An amount } of { TAIL ~ exhaust } coming out of each opening 48 may be the same or may be different
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH