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