\begin{table}%t4
\caption{\label{t4}Derived physical quantities of the \HII\ regions.}
%\centering
\par
\begin{tabular}{cccccccc}
\hline\hline
\noalign{\smallskip}
Name & $d$ & $D$ & $U$ & $n_{\rm e}$ & $N_{\rm Ly}$ & $L_{\rm bol}$ & Spectral \\
     & (kpc) & (pc) & (pc cm$^{-2}$) & (cm$^{-3}$) & (10$^{46}$ s$^{-1}$) & ($L_{\odot}$) & Type \\
\hline
\multicolumn{8}{c}{\HII\ regions spatially coincident with H$_2$O masers} \\
G32.74--0.07  &  2.7 & $\le$0.01 & 10 & 4 $\times$ 10$^5$ & 3.1 & 1.3 $\times$ 10$^4$ & B0.5 \\
G35.03+0.35B &  3.6 & $\le$0.01 & 5 & 2 $\times$ 10$^3$ & 0.3 & 6.3 $\times$ 10$^3$ &  B1 \\
G35.20--0.74  &  2.2 & 0.07 & 2 & 1 $\times$ 10$^4$ & 0.02 & 2.0 $\times$ 10$^3$ & B2 \\
\hline
\multicolumn{8}{c}{\HII\ regions not associated with H$_2$O masers} \\
G12.22--0.12  &      16.1 & 0.43 & 54 & 4 $\times$ 10$^3$ & 501.6 & 1.1 $\times$ 10$^5$ & O6.5 \\
G31.28+0.06  &       8.5 & 0.23 & 32 & 6 $\times$ 10$^3$ & 101.0 & 4.3 $\times$ 10$^4$ & O9 \\ 
G31.24--0.11  &  1.7 & 0.03 & 15 & 2 $\times$ 10$^4$ & 10.1 & 1.9 $\times$ 10$^4$ & B0 \\ 
G31.21--0.18 &      19.7  & $\le$0.03 & 22 & 1 $\times$ 10$^6$ & 35.3 & 2.9 $\times$ 10$^4$ & B0 \\ 
G35.03+0.35A &  3.6 & $\le$0.01 & 8 & 17 $\times$ 10$^4$ & 1.7 & 1.1 $\times$ 10$^4$ & B0.5 \\ 
G35.20--1.74A &       3.3 & 0.03 & 46 & 1 $\times$ 10$^5$ & 301.0 & 7.9 $\times$ 10$^4$ & O7.5/O8 \\ 
G35.20--1.74B &       3.3 & 0.05 & 24 & 2 $\times$ 10$^4$ & 42.7 & 3.1 $\times$ 10$^4$ & O9.5/B0 \\ 
G43.89-0.38  &       4.2 & 0.14 & 27 & 8 $\times$ 10$^3$ & 63.3 & 3.6 $\times$ 10$^4$ &  O9.5 \\ 
G48.61+0.02  &      9.7 & 0.11 & 20 & 3 $\times$ 10$^4$ & 51.1 & 2.5 $\times$ 10$^4$ & B0 \\ 
G50.32+0.68  &       8.7 & 0.18 & 25 & 5 $\times$ 10$^3$ & 51.1 & 3.4 $\times$ 10$^4$ & O9.5 \\ 
G75.78+0.34  &       4.1 & 0.03 & 10 & 2 $\times$ 10$^4$ & 2.9 & 1.3 $\times$ 10$^4$ & B0.5 \\ 
\hline
\end{tabular}
\end{table}