\begin{table}%[ht!]%t7
%\begin{center}
\par
\caption{Best-fit decay indexes of the early optical emission for all GRBs with well monitored optical counterpart that shows a steep-to-shallow behavior (Fig.~\ref{test}).}
\begin{tabular}{ccccccc}
\hline  \hline 
GRB    & Filter & $\alpha_1$	 &   $\alpha_2$  &  $t_{{\rm break}}$  & $z$ \\
	&	&		&		& 	(s)	&	\\
\hline
990123$^{(1)}$ &  $V$  & $\sim$2.5  & $\sim$1.5 & 700  & 1.60	 \\
021211$^{(2)}$ &  $R$  &$1.97\pm0.05$  & $1.01\pm0.02$ & 300	 &1.0\\
060117$^{(3)}$ &  $R$  & $2.49\pm0.05$  & $1.47\pm0.03$ & 300	 &1$^{a}$\\
061126$^{(4)}$ &  $R$  & $2.0\pm0.3$  & $0.76\pm0.06$ & 780 & 1.1588\\
%061121 &-& $2.2\pm0.4$ & $0.7$ & &\\
060111B &  $R$  & $2.4 \pm 0.2$  & $1.18\pm0.05$ & 75 & 2\\
080319B$^{(5)}$&  $R$  & $2.49\pm0.09$  & $1.25\pm0.02$ & 900&0.937  \\
090102$^{(6)}$&  $R$  & $1.83\pm0.13$  & $1.1\pm0.3$ & 400 &1.547 \\
\hline
\end{tabular}
\label{lc_opt}
%\end{center}
\par
\begin{list}{}{}
\item[$^{a}$] For GRB 060117 since the redshift is not known, we imposed $z=1$.
\end{list}
References. (1) \cite{Akerlof1999}; (2) \cite{Holland2004}; (3) \cite{Jelinek2006}; (4) \cite{Perley2008}; (5) \cite{Racusin2008b}; (6) \cite{Klotz2009}. 
\end{table}