{HEAD ~ The exposed portion} of the membrane 24 is provided with {TAIL ~ a through hole} 30 
is provided with
{ HEAD ~ The exposed portion } of the membrane 24 is provided with { TAIL ~ a through hole } 30
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH