@array = qw( is an to  for from);
@strs =("is that true","this is from presentation","to create");
print "\n---- INPUT ----\n";
print join("\n",@strs);

$subs=join("|",@array);

map{s/\b$subs\b//g} @strs;
print"\n---- OUTPUT ----\n";
print join("\n",@strs);