{HEAD ~ A method} of detection for parcels is to ensure {TAIL ~ separation} is performed by mechanical equipment prior to directing the sensing devices towards the parcel 
is to ensure
{ HEAD ~ A method } of detection for parcels is to ensure { TAIL ~ separation } is performed by mechanical equipment prior to directing the sensing devices towards the parcel
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH