2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/216172We calculate the two-boson-exchange (TBE) corrections to the parity-violating asymmetry of the elastic electron-proton scattering in a simple hadronic model including the nucleon and the $Δ(1232)$ intermediate states. We find that $Δ$ contribution $δ_Δ$ is, in general, comparable with the nucleon contribution $δ_N$ and the current experimental measurements of strange-quark effects in the proton neutral weak current. The total TBE corrections to the current extracted values of $G^{s}_{E}+βG^{s}_{M}$ in recent experiments are found to lie in the range of $-7\sim +7%$.3 pages, 2 figs, 1 table, talk given at International Conference of Particle and Nuclei (PANIC08) Eilat, Israel, 9-14 Nov,2008Nuclear Theorytext