{HEAD ~ The initiating constituent} is usually present in {TAIL ~ an amount} of about 0.05 to about 5 percent by weight of the copolymer 
is usually present in
{ HEAD ~ The initiating constituent } is usually present in { TAIL ~ an amount } of about 0.05 to about 5 percent by weight of the copolymer
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH