  Gamma rays in the band from 30 MeV to 300 GeV, used in combination with
direct measurements and with data from radio and X-ray bands, provide a
powerful tool for studying the origin of Galactic cosmic rays. Gamma-ray Large
Area Space Telescope (GLAST) with its fine 10-20 arcmin angular resolution will
be able to map the sites of acceleration of cosmic rays and their interactions
with interstellar matter. It will provide information that is necessary to
study the acceleration of energetic particles in supernova shocks, their
transport in the interstellar medium and penetration into molecular clouds.
