Complex sentence: She competed in the scratch event at the 2012 UCI Track Cycling World Championships switched to keirin racing in 2014 to focus on an Olympic event which she was successful in qualifying for Rio 2016.
Split into simpler sentences: She competed in the scratch event at the 2012 UCI Track Cycling World Championships. She switched to keirin racing in 2014 to focus on an Olympic event which she was successful in qualifying for Rio 2016.