{HEAD ~ at least first and second openings} configured to allow {TAIL ~ fluids} to flow into the first opening and out of the second opening 
configured to allow
{ HEAD ~ at least first and second openings } configured to allow { TAIL ~ fluids } to flow into the first opening and out of the second opening
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH