\begin{table}%t2 %\centering \par \caption{\label{cloud_param}Summary of the parameters of the four molecular clouds identified in the FCRAO $^{13}$CO(1--0) emission.} \begin{tabular}{c c c c c} \hline\hline \noalign{\smallskip} Cloud & $\Delta~v$ & $d_{\rm FAR}$ & $d_{\rm NEAR}$ & $D_{\rm GC}$ \\ & (km~s$^{-1}$) & (kpc) & (kpc) & (kpc) \\ (1)&(2)&(3)&(4)&(5)\\ \hline 1 & 28--32 & 13.4 & 2.6 & 6.1 \\ 2 & 33--48 & 12.6 & 3.4 & 5.4 \\ 3 & 54--63 & 11.7 & 4.3 & 4.7 \\ 4 & 64--73 & 11.3 & 4.7 & 4.3 \\ \hline \end{tabular} \tablefoot{Column~(1): the cloud; Col.~(2): the velocity interval of the emission; Col.~(3): the far distance; Col.~(4): the near distance; Col.~(5): the galactocentric distance.} \vspace*{5mm} \end{table}