Complex sentence: The Canadian men's national under 18 ice hockey team is part of a three-stage Program of Excellence beginning with the Under-17 regional teams and ending with the National Junior Team.
Split into simpler sentences: The Canadian men's national under 18 ice hockey team is the national under-18 team in Canada. This team is part of a three-stage Program of Excellence beginning with the Under-17 regional teams and ending with the National Junior Team.