\begin{table}%T1
\caption{\label{tab1}Central star temperatures and nebular parameters. Chemical abundances are expressed in $12+\log~(X$/H).
The line fluxes $F_{\rm H\alpha}$ and $F_{\rm [OIII]}$ as observed by~M~00. The adopted reddening correction is $E(B-V)=0.07$ 
(van~den~Bergh \cite{bergh}).}  
%\begin{center}
{
\begin{tabular}{r r r r l l l l r r r r r r }    
\hline    \hline   
Id  & $d$ & $F_{\rm H\alpha}$ & $F_{\rm [OIII]}$ & $T_{\star}$ & log~($L_{\star}$/$L_{\odot}$)     & log~($r$)  & log~($N_{\rm e}$) & He/H &~N/H &~O/H & S/H & Ar/H & N/O \\
M~00 & arcmin &\multicolumn{2}{c}{\footnotesize{10$^{-15}$~erg/cm$^{2}$~s}}&K/1000& 	&cm &~cm$^{-3}$ &    &   &   &  &  &    \\
\hline  
8   &22 & 11.4 & 10.1 & 74~b  & 3.8 &$16 <r<18$~d    & 3.1 &  11.05 &7.07 &7.94 &6.38 &6.11&      $-0.87$               \\
18  &13 & 3.0  & 14.2 & 100~b & 4.1 &$16 <r<17.9$~d  & 2.5 &  11.09 &7.48 &8.20 &6.83 &6.51&       $-0.72$\\
28  &12 & 2.9  & 13.9 & 142~a & 3.7 &$16 <r<17.7$~d  & 2.1 &  10.96 &6.98 &8.69 &6.47 &6.3&       $-1.71$\\
60  &13 & 1.4  & 3.4  & 160~a  & 3.1 & 17~c           & 2.9 & 11.04 &7.67 &8.69 &6.57 &6.31&       $-1.02$\\
65  &8  & 10.1 & 5.6  & 128~b  & 3.2 &$16 <r<17.7$~d& 3.2 & 11.16 &7.61 &8.67 &6.84 &6.63&       $-1.06$\\
75  &11 & 4.4  & 12.5 & ~96~b  & 3.5 &$16 <r<17$~d    & 3.9 & 11.14 &8.03 &8.49 &6.81  &6.41&	$-0.46$\\
91  &18 & 4.9  & 16.3 & 110~a  & 3.6 &17.0~c	      & 3.6 & 11.31 &8.07 &8.48 &6.60 &6.18&      $ -0.41$\\
93  &16 & 3.1  & 7.4  & ~96~a  & 3.3 &17.2~c	      & 3.7 & 10.93 &7.75 &8.47 &6.66 &6.09&       $-0.72$\\
96  &9  & 3.1  & 11.9 & 105~b  & 3.5 &$16< r <17.9$~d & 1.9 & 11.06 &7.43 &8.76 &6.44 &6.33&       $-1.33$\\
101 &14 & 4.1  & 11.4 & ~97~b  & 3.4 & 17~c	      & 2.5 & 11.07 &7.33 &8.72 &6.18 &6.27&      $ -1.56$\\
125 &9  & 7.5  & 8.2  & ~86~b  & 3.6 & $16< r <17.9$~d& 2.2 & 10.93 &7.53 &8.31 &6.66 &6.14&       $-0.78$\\
\hline
\multicolumn{4}{l}{M~33~PNe all (1)}   	                && &  & & 11.08 &7.65  & 8.54 &6.62  &6.33 &$-0.89$\\
\multicolumn{4}{l}{M~33~PNe with $T_{\star}$ measured (1)}   &   & &  & & 11.09 &7.78  &8.61  &6.60  &6.28 &$-0.83$\\
\multicolumn{4}{l}{M~33 \hii~regions (2)} &  &             &       &  & 10.92 &7.34  &8.55  &6.95  &$-$     & $-1.21$  \\
\hline
\multicolumn{4}{l}{Galactic~PNe non-type I (3)}  &               &  & & & 11.05 &8.14  & 8.69  &6.91  &6.38&$-0.55$\\
\multicolumn{4}{l}{Galactic~PNe type I (3)}  &               &      &&  & 11.12 &8.72  & 8.65  &6.91  &6.42&+0.07\\
\multicolumn{4}{l}{Galactic \hii~regions (4)}         &    & &       &  & 11.00 &7.57  & 8.70  &7.06  &6.42&$-1.13$\\
\hline
\multicolumn{4}{l}{LMC~PNe non-type I (5)}                 & &     & &  & 10.96  &7.46   &8.35   &6.81   &5.95 &$-0.90$\\
\multicolumn{4}{l}{LMC~PNe type I (5)}                  &   &  &       & & 10.95  &8.28   &8.24   &7.11   &6.12 &+0.02\\
\multicolumn{4}{l}{LMC \hii~regions (6)}    &    &      &   &         & 10.97  &6.97   &8.38   &6.67   &6.92 &$-1.41$\\
\hline
\end{tabular}}
(1) Present paper (average, by number, not by $\log$).  \\
(2) V\'{\i}lchez et~al. (\cite{vilchez88}).   \\
(3) KB~94.   \\
 (4) Dufour (\cite{dufour84}).  \\
 (5) Leisy \& Dennefeld (\cite{leisy04}).    \\
 (6) Dennefeld (\cite{dennefeld}).   
%\end{center}
\end{table}