  Current universe (assumed here to be normal matter on the brane) is
pressureless from observations. In this case the energy condition is
$\rho_0\geq0$ and $p_0=0$. By using this condition, brane models can be
distinguished. Then, assuming arbitrary component of matter in DGP model, we
use four known energy conditions to study the matter on the brane. If there is
nonnormal matter or energy (for example dark energy with $w<-1/3$) on the
brane, the universe is accelerated.
