Complex sentence: Bradbury was allocated to the same race as Apolo Anton Ohno (the favourite from the host nation) and Marc Gagnon of Canada (the defending World Champion), and only the top two finishers from each race would proceed to the semifinals.
Split into simpler sentences: Bradbury was allocated to the same race as Apolo Anton Ohno, the favourite from the host nation, and Marc Gagnon of Canada, the defending World Champion. Only the top two finishers from each race would proceed to the semifinals.