broad band V and I data assuming that the continuum can be represented by a simple power law, of the form $f_{\lambda} \propto \lambda^{\beta}$: the median values for the two sub-sample are $\beta=-1.15\pm0.11 $ for  and $-1.33\pm0.12$ for . Again, this difference indicates that there is a diversity in dust extinction between the two sub-samples. We note that, although the trend is similar to that found by Shapley et al. (2003), they report slightly redder slopes for their LBGs for a given EW, ranging from -0.73 for the absorbers to -1.1 for the strongest emitters (but their beta values are evaluated from the G-R colors, while our slopes are from V and I band data). On the other hand our values are similar to that reported by Hathi et al. (2008) for z$\sim 3 $ LBGs, which is $\beta =-1.1\pm 0.2$ and by Adelberger & Steidel (2000), which is $\beta =-1.5\pm 0.4$.\
We finally report a significant, although very scattered correlation between the total stellar mass and the extinction, in the sense that the most massive galaxies tend to show more dust.

SFR from UV continuum and SED fitting
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There are different ways of estimating the star formation rates 