{HEAD ~ The rate} of hardening, or {TAIL ~ polymerization}, of adhesive can be controlled by varying the concentration of catalyst in the catalyst solution 
of
{ HEAD ~ The rate } of hardening , or { TAIL ~ polymerization } , of adhesive can be controlled by varying the concentration of catalyst in the catalyst solution
HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH