Complex sentence: In 2007, the line was extended to Pinar De Chamartin in two stages, firstly, on 30 March 2007, the line was extended from Plaza De Castilla to Chamartin, which provides interchange with Line 10 and RENFE services.
Split into simpler sentences: In 2007, the line was extended to Pinar De Chamartin in two stages. First, on 30 March 2007, the line was extended from Plaza De Castilla to Chamartin, which provides interchange with Line 10 and RENFE services.