When certified copies of the proceedings for annexation are filed as contemplated in section 31-12-412, the annexation shall be complete, and the city or town to which the annexation is made has the power to pass such ordinances, not inconsistent with law, as will carry into effect the terms of such annexation. Thereafter, the city or town annexed shall be governed as part of the city or town to which it is annexed. Such annexation shall not affect or impair any rights or liabilities then existing for or against either of such cities or towns, and they may be enforced the same as if no such annexation had taken place.