{TAIL ~ An intake air duct} serving as a passage for supplying {HEAD ~ air} to an engine, the intake air duct comprising: 
{ TAIL ~ An intake air duct } serving as a passage for supplying { HEAD ~ air } to an engine , the intake air duct comprising :
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH