  Inclusive electromagnetic reactions in few-nucleon systems are studied basing
on accurate three- and four-body calculations. The longitudinal 4He(e,e')
response function obtained at q\le 600 MeV/c completely agrees with experiment.
The exact 4He spectral function obtained in a semirealistic potential model is
presented, and the accuracy of the quasielastic response calculated with its
help is assessed, as well as the accuracy of some simpler approximations for
the response. The photodisintegration cross section of 3He obtained with the
realistic AV14 NN force plus UrbanaVIII NNN force agrees with experiment. It is
shown that this cross section is very sensitive to underlying nuclear dynamics
in the E_\gamma\simeq 70-100 MeV region. In particular, the NNN nuclear force
clearly manifests itself in this region.
