Complex sentence: He was selected for the Czech national team for the 1946 European Championships and finished fifth in the 5K, breaking his own Czech record of 14:50.2, running 14:25.8.
Split into simpler sentences: He was selected for the Czech national team for the 1946 European Championships. He finished fifth in the 5K, breaking his own Czech record of 14:50.2, running 14:25.8.