{HEAD ~ The agent} acts as {TAIL ~ a means} to control the degradation of the composite and the glass fiber 
acts as
{ HEAD ~ The agent } acts as { TAIL ~ a means } to control the degradation of the composite and the glass fiber
HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH