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