Complex sentence: Josef Erleback was a Czechoslovakian Nordic skier who competed in Cross-country skiing in the 1920's; he won a bronze medal in the 18 km event at the 1925 FIS Nordic World Ski Championships.
Split into simpler sentences: Josef Erleback was a Czechoslovakian Nordic skier who competed in Cross-country skiing in the 1920's. He won a bronze medal in the 18 km event at the 1925 FIS Nordic World Ski Championships.