  The Friedman equation for the universe with arbitrary curvature $(k = 0, \pm
1)$, filled with mutually noninteracting pressureless dust, radiation,
cosmological constant, and strings is considered. We assume the string
domination scenario for the evolution of the latter component. Moreover, we
discuss the simplest possibility for the scaling of the string energy density:
$\varrho \propto R^{-2}$. For such models we write down the explicit solution
of the Friedman equation. We realize that corresponding cosmological models do
not essentially differ from those without strings. We find an analytic formula
for the radial coordinate $\chi$ of a galaxy with a redshift z and express it
in terms of astronomical parameters. This relation is then used for the
derivation of the astrophysical formulas such as luminosity distance, angular
diameter, and source counts, which may serve for testing the string-dominated
universe. It seems that the most sensitive test, at least from the formal point
of view, is the formula for the number of galaxies $N(z)$ corresponding to a
given value of the redshift. We show that the maximum of $N(z)$ strongly
depends on the density of strings, especially if the density is large enough to
explain the $\Omega$ problem. Other tests are also proposed.
