Complex sentence: The line opened on 15 January 2007, with three stations along its 2.1 kilometre double-track route and a second station, Waterfront, will open in 2010 when Sentosa Resorts World is completed.
Split into simpler sentences: The line opened on 15 January 2007, with three stations along its 2.1 kilometre double-track route. A fourth station, Waterfront, will open in 2010 when Resorts World Sentosa is completed.