A hybrid vehicle in which an engine can always be driven in {HEAD ~ a highly efficient region} in {TAIL ~ accordance} with the required running load 
in
A hybrid vehicle in which an engine can always be driven in { HEAD ~ a highly efficient region } in { TAIL ~ accordance } with the required running load
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH