The contribution of the two-nucleon emission in the longitudinal respo
nse for inclusive electron scattering reactions is studied. The model
adopted to perform the calculations is based upon correlated basis fun
ction theory but it considers only first order terms in the correlatio
n function. The proper normalization of the wave function is ensured b
y considering, in addition to the usually evaluated two-point diagrams
, the three-point diagrams. Results for the C-12 nucleus in the quasie
lastic region are presented.