  Unified description on the long-time tail of velocity autocorrelation
function and the long-range correlation for the equal-time spatial correlation
functions is developed based on the generalized fluctuating hydrodynamics. The
cross-over of the long-time tail from $t^{-3/2}$ to $t^{-5/2}$ is predicted
independent of the density, and the equal-time spatial density correlation
function and the equal-time spatial velocity correlation function respectively
satisfy $r^{-11/3}$ and $r^{-5/3}$ for large $r$ limit.
