{HEAD ~ An exhaust channel} is defined in the base portion and communicating with {TAIL ~ the at least one membrane electrode assembly} 
communicating with
{ HEAD ~ An exhaust channel } is defined in the base portion and communicating with { TAIL ~ the at least one membrane electrode assembly }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL