  This paper is devoted to the temperature dependence of the resistivity in Si-
MOS samples over the wide range of densities in the ``metallic phase'' (n>n_c)
but not too close to the critical density n_c. Three domains of different
behavior in \rho(T) are identified. These are: [i] quantum domain of
`low-temperatures', where a logarithmic T-dependence of \rho (with
$d\rho/dT<0$) dominates; [ii] semi-classical domain of `high-temperatures', in
which Drude resistivity strongly varies with T (with d\rho/dT>0); and [ii]
crossover between the former two, where a linear T-dependence dominates (with
d\rho/dT>0). In the crossover regime and at higher densities
(n>20x10^{11}/cm^2), \rho(T) goes through a minimum at temperature T_{min}.
Both the absolute value of T_{min} and its dependence on density are found to
be in an agreement with the conventional weak-localization theory. For n
smaller than \sim 20x10^{11}/cm^2, the theoretical estimate for T_{min} falls
outside the experimentally accessible temperature range. This explains the
absence of the minimum at these densities in the data. In total, over the two
decades in the temperature (domains [ii] and [iii]), the two semiclassical
effects mimic the metallic like transport properties. Our analysis shows that
the behaviour of \rho(T) in the region of \rho << h/e^2 can be described
phenomenologically in terms of the conventional weak-localization theory.
