  The resistivity $\rho$ of high mobility dilute 2D holes in GaAs exhibits a
peak at a certain temperature $T^*$ in zero magnetic field($B$=0). In the
$T>T^*$ regime where d$\rho$/d$T<$0, we observe for the first time both the
$\nu=1$ quantum Hall(QH) effect and a low field insulator-QH transition which
is consistent with the 2D hole system being a Fermi liquid(FL). The known
linear $T$-dependent conductivity in this $T$ regime then can be explained by
hole-hole Coulomb interactions of this FL. The fact that the system is metallic
(d$\rho$/d$T>$0) for $T<T^*$ implies that the high temperature FL transforms
into the 2D metallic state in the neighborhood of $T^*$.
