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