as an area of $>100$ arcmin$^{2}$ is required to find one single object as massive as our mass-selected galaxies. The different stellar mass regime probed by the two samples suggests that lower-mass galaxies are characterized by much bluer rest-frame UV-optical colors than the most massive galaxies at these redshifts. This is also supported by the different rest-frame UV properties between our mass-selected sample and typical UV-selected $B$- and $V$-dropout samples, which have stellar masses in the range $10^{9}-10^{11}$ M$_{\sun}$ (e.g, @shapley01; @magdis10). From the SED modeling analysis, it appears that the differences in the rest-frame UV properties between the $H-K$-selected galaxies and our mass-selected sample could be primarily due to the different amount of dust in the two samples, as their typical stellar ages ($\sim1-1.5$ Gyr) are broadly consistent within the uncertainties. More specifically, the $H-K$-selected galaxies from @brammer07 are characterized by a median dust extinction of $\langle A_{\rm V}\rangle \sim 0.2$, a factor of about $\sim7$ smaller than the median extinction of our mass-selected sample ($\langle A_{\rm V} \rangle=1.4$ mag). Indeed, significant amount of dust seems to be quite ubiquitous in massive galaxies at $3.0 \leq z < 4.0$. The amount of dust in our mass-selected sample is significantly 