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