Complex sentence: The Sir Winston Churchill Robodogs have been competing in the First Technology Challenge (2007-2009) and the VEX robotics competitions (2009-Present), and competed in the world championships four years in a row (2008-2011).
Split into simpler sentences: The Sir Winston Churchill Robodogs have been competing in the First Technology Challenge (2007-2009) and the VEX robotics competitions (2009-Present). They competed in the world championships four years in a row (2008-2011).