All parts, percentages and {HEAD ~ ratios} used herein are expressed by {TAIL ~ weight} unless otherwise specified 
are expressed by
All parts , percentages and { HEAD ~ ratios } used herein are expressed by { TAIL ~ weight } unless otherwise specified
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH