The projection extends from a rim of the hole and {HEAD ~ the hollow} is in {TAIL ~ communication} therewith 
The projection extends from a rim of the hole and { HEAD ~ the hollow } is in { TAIL ~ communication } therewith
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH