\begin{tikzpicture}[scale=0.25]
\draw (0,-5)--(0,-0.5);
\foreach \x in {0,3,6}{
\begin{scope}[xshift=\x cm]
  \coordinate (O) at (0,0) ;
 \coordinate (A) at (1,0) ;
 \coordinate (B) at (2,0) ;
 \coordinate (C) at (3,0) ;
 \coordinate (D) at (1,-4.5) ;
 \coordinate (E) at (2,-4.5) ;
 \coordinate (F) at (0,-5) ;
 \coordinate (G) at (3,-5) ;
 \coordinate (H) at (3,-0.5) ;
 
 \draw (O)--(A)--(B)--(C)
	(F)--(G)
	(A)--(D)
	(B)--(E)
	(G)--(H);
\end{scope}
}

\end{tikzpicture}