Complex sentence: President Barack Obama and First Lady Michelle Obama traveled to Denmark to support Chicago bid for the 2016 Summer Olympics in October 2009, and again in December 2009, Obama visited Denmark again for the 2009 United Nations Climate Change Conference.
Split into simpler sentences: President Barack Obama and First Lady Michelle Obama traveled to Denmark to support Chicago bid for the 2016 Summer Olympics. In December 2009, Obama visited Denmark again for the 2009 United Nations Climate Change Conference.