  The particle acceleration process at a shock wave, in the presence of the
second-order Fermi acceleration in the turbulent medium near the shock, is
discussed as an alternative explanation for the observed flat synchrotron
spectra of supernova remnants (SNRs) in molecular clouds. We argue that medium
Alfv\'en Mach number shocks considered by Chevalier (1999, ApJ, in press) for
such SNRs can naturally lead to the observed spectral indices.
