sentences:  Prior to World War II, due to major limestone deposits in Opole's vicinity, the city developed as a centre for cement production in Germany, with the "Cementownia "Odra"" being active till this day.The French building materials company Lafarge is also active in the area, having its roofing division, Lafarge Roofing, together with its German subsidiary Schiedel (chimney manufacturing) based in Opole.Other companies in the city include