2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47514Symmetries concerning the ordinary coordinate spacetime and internal spacetime are discussed. A possible unification model of electroweak, strong and gravitational interactions is briefly described.14 pages, latex, Talk presented in the International Conference on Physics Since Parity Symmetry Breaking (A conference in memory of Madame C.S. Wu) August 16-18, 1997 Nanjing, to appear in the ProceedingsHigh Energy Physics - Phenomenologytext