\begin{table}%t4
%\centering
\par
\caption{Abundances in the 1D static envelope model derived from of
single-dish line observations. For details see
\cite{paperii}.\label{assumed_abundances}}
\begin{tabular}{ll} \hline\hline
Molecule & Abundance ([$X$/H$_{2}$]) \\ \hline
C$^{34}$S                    & $1.4\times 10^{-10}$ \\
CS                       & $1.3\times 10^{-9}$  \\
H$^{13}$CO$^+$ (all except 1--0 line) & $4.3\times 10^{-11}$ \\
H$^{13}$CO$^+$ (1--0 line)       & $8.0\times 10^{-11}$ \\ \hline
\end{tabular}
\end{table}