the first trap unit further includes a collection unit for collecting {HEAD ~ the debris} molten on the surface of {TAIL ~ the first trap unit} 
the first trap unit further includes a collection unit for collecting { HEAD ~ the debris } molten on the surface of { TAIL ~ the first trap unit }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL