Complex sentence: They improved to 8th and 12th, respectively, in 2005, and in 2006 were chosen to represent Great Britain at the 2006 Winter Olympics, where they finished 10th.
Split into simpler sentences: They improved to 8th and 12th, respectively, in 2005. In 2006 they were chosen to represent Great Britain at the 2006 Winter Olympics, where they finished 10th.