\begin{table}%t3
\caption{Rest-frame equivalent widths in \AA{} of prominent lines in the 
composites of the three GMASS subsamples at $1.5 < z < 2.5$.}
\label{tab_ews}
%\centering
\par
\begin{tabular}{l @{} c c c c}
\hline\hline
%\noalign{\smallskip}
Line & Type$^{a}$ &
$\gamma_{34} > -2$     & $\gamma_{34} > -2$     & $\gamma_{34} < -2$ \\
     &          &
$\beta_{\rm b} < -1.5$ & $\beta_{\rm b} > -1.5$ &                    \\ 
%\noalign{\smallskip}
\hline
%\noalign{\smallskip}
Si~IV~$\lambda$~1400  & is & 
$+3.18 \pm 0.50$ & $+2.90 \pm 0.63$ & $+4.06 \pm 0.75$ \\
S~V~$\lambda$~1502    & s  & 
$+0.55 \pm 0.09$ & $+0.60 \pm 0.07$ & $+0.83 \pm 0.11$ \\
Si~II~$\lambda$~1526  & i  & 
$+1.97 \pm 0.12$ & $+1.95 \pm 0.17$ & $+2.73 \pm 0.28$ \\
C~IV~$\lambda$~1550   & si & 
$+4.48 \pm 0.36$ & $+4.52 \pm 0.54$ & $+5.65 \pm 0.32$ \\
Fe~II~$\lambda$~1608  & i  & 
$+1.36 \pm 0.15$ & $+1.72 \pm 0.12$ & $+1.72 \pm 0.27$ \\
He~II~$\lambda$~1640  & sn & 
$-1.14 \pm 0.27$ & $-1.23 \pm 0.35$ & $-1.29 \pm 0.28$ \\
Al~II~$\lambda$~1670  & i  & 
$+1.43 \pm 0.08$ & $+1.53 \pm 0.14$ & $+2.04 \pm 0.18$ \\
Al~III~$\lambda$~1860 & i  & 
$+2.61 \pm 0.20$ & $+3.11 \pm 0.22$ & $+3.66 \pm 0.20$ \\
C~III]~$\lambda$~1907 & n  & 
$-1.05 \pm 0.14$ & $-1.48 \pm 0.14$ & $-1.16 \pm 0.22$ \\
C~II]~$\lambda$~2326  & n  & 
$-1.03 \pm 0.22$ & $-1.63 \pm 0.21$ & $-0.92 \pm 0.21$ \\
Fe~II~$\lambda$~2344  & i  & 
$+1.97 \pm 0.35$ & $+2.07 \pm 0.19$ & $+2.95 \pm 0.26$ \\
Fe~II~$\lambda$~2380  & i  & 
$+3.16 \pm 0.32$ & $+3.67 \pm 0.24$ & $+4.83 \pm 0.29$ \\
Fe~II~$\lambda$~2600  & i  & 
$+4.79 \pm 0.48$ & $+5.15 \pm 0.62$ & $+5.85 \pm 0.68$ \\
Mg~II~$\lambda$~2800  & is & 
$+4.01 \pm 0.75$ & $+4.02 \pm 0.73$ & $+6.59 \pm 0.76$ \\
Mg~I~$\lambda$~2852   & s  & 
$+0.30 \pm 0.19$ & $+0.83 \pm 0.25$ & $+1.30 \pm 0.34$ \\
%\noalign{\smallskip}
\hline
\end{tabular}
\begin{list}{}{}
\item[$^{a}$] Line origin: s = stellar (photosphere and/or wind), 
i = interstellar absorption, n = nebular emission.
\end{list}
\end{table}