\begin{table}%t2
%\centering
\par
\caption{\label{abund_tab_ctq}Abundance measurements (and 3$\sigma$ upper limits)
for CTQ247. $^a$ uses AODM; $^b$ $N({\rm Al})=N(\ion{Al}{ii})+N(\ion{Al}{iii})$.}
\begin{tabular}{ccccccc}
\hline \hline
\noalign{\smallskip}
  & \multicolumn{2}{c}{CTQ247A} & \multicolumn{2}{c}{CTQ247B} & \multicolumn{2}{c}{CTQ247C}  \\
X &  $N$(X) &  [X/H]&  $N$(X) &  [X/H] & $N$(X) &  [X/H]\\ \hline\noalign{\smallskip}
\ion{H}{i} & $21.13\pm0.10$ & ... & $21.09\pm0.10$  & ... & $20.47\pm0.10$ &...  \\
\ion{N}{i}  & $14.55\pm0.03$ & $-2.51\pm0.10$ & $15.07\pm0.02$ & $-1.95\pm0.10$ & $<14.36$ & $<$$-2.04$  \\ 
\ion{O}{i} &  ...& ... &...  & ... & $15.19\pm0.02$ & $-2.02\pm0.10$   \\
\ion{Al}{ii} & ...  & ... & ...  & ... & $12.88\pm0.07$ &$-1.97\pm0.12^b$    \\
\ion{Al}{iii} &  $12.81\pm0.05^a$& ... & $12.63\pm0.04^a$  & ... & $12.33\pm0.03^a$ & ...  \\
\ion{Si}{ii} & $15.32\pm0.04$ & $-1.37\pm0.11$ & $15.59\pm0.03$ & $-1.06\pm0.10$ & $13.99\pm0.06$ & $-2.04\pm0.12$  \\
\ion{P}{ii} & $<$$13.15$ & $<$$-1.54$ & $<$$12.98$ & $<$$-1.67$ & ... & ...  \\
\ion{S}{ii}  & $14.82\pm0.06$ & $-1.51\pm0.12$ & $15.19\pm0.05$ & $-1.10\pm0.11$ & $<$$14.34$ & $<$$-1.33$  \\
\ion{Cr}{ii} & $13.20\pm0.03$ & $-1.62\pm0.10$ & $13.37\pm0.04$ &$-1.41\pm0.11$&...&... \\
\ion{Mn}{ii} & $12.86\pm0.02^a$ & $-1.80\pm0.10$ & $12.87\pm0.01^a$ &$-1.75\pm0.10$ & ... & ...  \\
\ion{Fe}{ii} & $14.95\pm0.06$ & $-1.68\pm0.12$ & $15.15\pm0.02$ & $-1.44\pm0.10$ & $13.60\pm0.02$ & $-2.37\pm0.10$  \\
\ion{Fe}{iii} &  ...& ... & $<$$13.66$  & ... & ... & ...  \\
\ion{Ni}{ii} & $13.94\pm0.02$ & $-1.44\pm0.10$ & $13.86\pm0.31$ & $-1.48\pm0.33$ & ... & ...  \\
\ion{Zn}{ii} & $12.44\pm0.05$ & $-1.36\pm0.11$ & $12.68\pm0.02$ & $-1.08\pm0.10$ & ... & ...  \\ \hline
 & & & & & & \\
\end{tabular}
\end{table}