{TAIL ~ A plurality} of {HEAD ~ mass gas flow controllers} are arranged to control flow into a respective inlet port 
{ TAIL ~ A plurality } of { HEAD ~ mass gas flow controllers } are arranged to control flow into a respective inlet port
TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH