Complex sentence: Advancement from Huin Ddi to Cho Dahn depends largely on the student's dedication and practice and thus achieving the rank of 1st Degree Black Belt could take anywhere from 4 to 6 years.
Split into simpler sentences: Advancement from Huin Ddi to Cho Dahn depends largely on the student's dedication and practice. Achieving the rank of 1st Degree Black Belt could take anywhere from 4 to 6 years.