A left-handed SU (2)L × U(1) × U′(1) electro/weak model (with Q = T3 + 1 2Y - 2 3L) is proposed. For neutrino interactions, our predictions are à la WS only with sin2ΘW → sin2ΘeffW < sin2W for processes which involve quarks, and (b) sin2ΘeffW (purely leptonic processes) > sin2ΘeffW (νq-scattering). For the polarized process eD → eX, the asymmetry parameter agrees with the WS one up to a second-order term. The additional neutral gauge boson is expected to be only one order of magnitude heavier than W±. We argue that the present neutral-current experimental results are not capable of distinguishing between the standard and the present models.