  We consider the first few virial coefficients of the osmotic pressure, the
radius of gyration, the hydrodynamic radius, and the end-to-end distance for a
monodisperse polymer solution. We determine the corresponding two-parameter
model functions which parametrize the crossover between the good-solvent and
the ideal-chain behavior. These results allow us to predict the osmotic
pressure and the polymer size in the dilute regime in a large temperature
region above the theta-point.
