Complex sentence: Work on the metro began again in 1948, in concert with turning the space, formerly designated for the Expo, into a commercial district under the name EUR. The metro was officially opened on 9 February 1955 by the then President of the Republic Luigi Einaudi.
Split into simpler sentences: Work on the metro began again in 1948, in concert with turning the space, formerly designated for the Expo, into a commercial district under the name Esposizione Universale Roma (EUR). The line was officially opened on 9 February 1955 by the then President of the Republic Luigi Einaudi.