{HEAD ~ The strength} of the bond can be varied by varying {TAIL ~ the amount} of the impregnant 
varied by varying
{ HEAD ~ The strength } of the bond can be varied by varying { TAIL ~ the amount } of the impregnant
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH