The structure includes a body for extending around the container opening and {HEAD ~ a membrane} for occluding {TAIL ~ the container opening} 
for occluding
The structure includes a body for extending around the container opening and { HEAD ~ a membrane } for occluding { TAIL ~ the container opening }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL