{TAIL ~ The process} 1 wherein said CO oxidation metal is added to {HEAD ~ said process} through said reaction zone 
{ TAIL ~ The process } 1 wherein said CO oxidation metal is added to { HEAD ~ said process } through said reaction zone
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH