A method 1 wherein {HEAD ~ the oxygen content} of the gas is from about 1% to {TAIL ~ about 100%} 
is to
A method 1 wherein { HEAD ~ the oxygen content } of the gas is from about 1 % to { TAIL ~ about 100 % }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL