The receiving portion has a space for pulling in {HEAD ~ the second end portion} of {TAIL ~ the stopper} 
of
The receiving portion has a space for pulling in { HEAD ~ the second end portion } of { TAIL ~ the stopper }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL