\begin{table}%t2
%\centering
\par
\caption{\label{tab_obs}Spectroscopic observations of GRB host galaxies from VLT/FORS2.}
\begin{tabular}{lcccccc}
\hline \hline  \noalign{\smallskip}
UT \ Date & Exposure \ time(second) & Seeing\tablefootmark{a}($''$)  & Grism & Program \ ID\\
\hline
GRB 980703  & & & & \\
2004.07.15-17   &  $8 \times 1200$ &  0.75 & 600Z & 073.B-0482(A)\\
2004.07.16-17   &  $8 \times 1200$ & 0.75  & 600RI  & 073.B-0482(A)\\
GRB 990712  &  &  &           & \\
2005.07.05-06 & $4 \times 1800$ & 0.59 &  300V   & 075.D-0771(A)\\
GRB 020405  &   &     &  & \\
2004.07.15-16   & $9 \times 1200$ &  0.70 & 600RI &   073.B-0482(A)\\
GRB 020903  &                &    &           & \\
2004.07.15      &  $6 \times 1200$ & 0.55  & 600B   &  073.B-0482(A)\\
2004.07.16      &  $6 \times 1200$ & 0.83  &  600RI  & 073.B-0482(A)\\
GRB 030329  &  &     &   & \\
2003.04.10      &  $6 \times 600$ &  1.18  &  300V &  071.D-0355(B)\\
2003.04.17      &  $2 \times 300$ &  0.71 &  300V & 071.D-0355(B)\\
2003.04.22      &  $1 \times 300$  &  0.71 &  300V & 071.D-0355(B)\\
2003.05.01      &  $2 \times 600$   &  0.51 & 300V & 071.D-0355(B) \\
2003.06.19      &  $3\times900$ &  0.75    & 300V &  271.D-5006(A)\\
GRB 031203  & & &   & \\
2003.12.20      &  $2 \times 2700$  & 0.50 & 300V &  072.D-0480(A)\\
2004.09.20      &  $2\times1800$       & 0.60        &   300V   &   {073.D-0255(A)}\\
2005.03.28      &  $4\times1200$       & 0.69 & 300V &  073.D-0418(A)\\
2005.04.09      &  $3\times1200$       & 1.26 & 300V &  075.D-0771(A)\\
GRB 060218  &  &      &           & \\
2006.11.27      &  $1 \times 3100$  & 0.97 &  300V  &  {078.D-0246(A)}\\
2006.12.19-20   &  $3 \times 3150$    & 0.72  & 300V & {078.D-0246(A)}\\
{GRB 060505}  &   &      &           & \\
2006.05.23      &  $2 \times 1800$ +1327+600   & 0.81   &  {300V} &  {077.D-0661(B)}\\
\hline
\end{tabular}
\tablefoot{\tablefoottext{a}{Seeing is the average value in the observing night.}}
   \end{table}