{HEAD ~ A system} replicates {TAIL ~ Internet websites} on a large number of user computers having browsers 
replicates
{ HEAD ~ A system } replicates { TAIL ~ Internet websites } on a large number of user computers having browsers
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH