Thus, {HEAD ~ the vehicle} can be converted into either a flatbed truck or {TAIL ~ a semi trailer truck} 
converted into
Thus , { HEAD ~ the vehicle } can be converted into either a flatbed truck or { TAIL ~ a semi trailer truck }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL