  Available data on large-angle nucleon-deuteron elastic scattering $Nd\to dN$
below the pion threshold give a signal for three-body forces. There is a
problem of separation of possible subtle aspects of these forces from off-shell
effects in two-nucleon potentials.
  By considering the main mechanisms of the process, we show qualitatively that
in the quasi-binary reaction $N+d\to (NN)+N$ with the final spin singlet
NN-pair in the S-state the relative contribution of the 3N forces differs
substantially from the elastic channel.
  It gives a new testing ground for the problem in question.
