a throttle valve disposed in {HEAD ~ an intake passage} of {TAIL ~ said internal combustion engine} for controlling the area of opening of said intake passage 
of
a throttle valve disposed in { HEAD ~ an intake passage } of { TAIL ~ said internal combustion engine } for controlling the area of opening of said intake passage
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH