Complex sentence: He continued his studies at Fitzwilliam College, Cambridge where he was awarded a master's degree in economics in 1975, he also served as the secretary of the university's student's union in 1973.
Split into simpler sentences: He continued his studies at Fitzwilliam College, Cambridge where he was awarded a master's degree in economics in 1975. He also served as the secretary of the university's student's union in 1973.