wherein one of said {TAIL ~ waste containers} fits into and fills each of {HEAD ~ said depressions} 
wherein one of said { TAIL ~ waste containers } fits into and fills each of { HEAD ~ said depressions }
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD