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