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