  We examine what we regard as key observational results on GRB 970228 and GRB
970508 and show that the accumulated evidence strongly suggests that gamma-ray
bursts (GRBs) are cosmological fireballs.
  We further show that the observations suggest that GRBs are not associated
with the nuclear activity of active galactic nuclei, and that late-type
galaxies are more prolific producers of GRBs.
  We suggest that GRBs can be used to trace the cosmic history of the
star-formation rate. Finally, we show that the GRB locations with respect to
the star-forming regions in their host galaxies and the total burst energies
can be used to distinguish between different theoretical models for GRBs.
