{TAIL ~ The gas} used in the present invention should contain {HEAD ~ at least about 70 mol percent hydrogen} 
{ TAIL ~ The gas } used in the present invention should contain { HEAD ~ at least about 70 mol percent hydrogen }
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD