The additive can be introduced into {TAIL ~ a combustion chamber} as {HEAD ~ part} of the fuel 
The additive can be introduced into { TAIL ~ a combustion chamber } as { HEAD ~ part } of the fuel
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH