\cline ¶Synopsis:
\cline{i-j}
In an array or tabular environment, draw a horizontal rule
beginning in column i and ending in column j. The
dash, -, must appear in the mandatory argument. To span a single
column use the number twice, as with \cline{2-2}.
This example puts two horizontal lines between the first and second rows, one line in the first column only, and the other spanning the third and fourth columns. The two lines are side-by-side, at the same height.
\begin{tabular}{llrr}
a &b &c &d \\ \cline{1-1} \cline{3-4}
e &f &g &h
\end{tabular}