The fugitive gases and the air enter {HEAD ~ the engine} 101 from {TAIL ~ the air intake} 120 through a control valve 133 
The fugitive gases and the air enter { HEAD ~ the engine } 101 from { TAIL ~ the air intake } 120 through a control valve 133
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH