"C<0=  2V9=8  ?@8E>2CT  @0=VH5  @>72V40=V  >1;0ABV,   O:V  =8=V  =5  ?>B@0?;ONBL  C  < l i n k = " t o p i c : l i n e   o f   s i g h t " > 7>=C  2848<>ABV< / l i n k > . 
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 "C<0=  2V9=8  ?>2' O70=89  7  < l i n k = " t o p i c : b l a c k   m a p " > G>@=8<8  4V;O=:0<8  <0?8< / l i n k >   B0  < l i n k = " t o p i c : l i n e   o f   s i g h t " > 7>=>N  2848<>ABV< / l i n k > . 