\begin{table}%t1
\caption{\label{ratios}\label{tab1}Elemental and molecular abundances measured in HD~189733b (from S09a).}
\small%\centering
\par
\begin{tabular}{lccc}
\hline
\hline 
Species X 	&  (X/H$_2$)   				& Species X 		&  (X/H$_2$) 				\\	
\hline
\noalign{\smallskip}
O			& $1.1{-}4 \times 10^{-4}$		& CO			& $1{-}3    \times 10^{-4}$		\\
C			& $1{-}3 \times 10^{-4}$		& CO$_2$		& $0.1{-}1 \times 10^{-6}$		\\
H$_2$O		& $0.1{-}1 \times 10^{-4}$		& CH$_4$		& $ \le$$1 \times 10^{-7}$		\\ 
\hline
\end{tabular} 
\end{table}