Complex sentence: From 1950 to 1951 Dr. Roland Renne was the president of the Water Resources Policy Commission, and from 1951 to 1953, he acted as chief of the Mutual Security Agency's Special Technological and Economic Mission to the Philippines.
Split into simpler sentences: From 1950 to 1951 he was the president of the Water Resources Policy Commission. From 1951 to 1953, he acted as chief of the Mutual Security Agency's Special Technological and Economic Mission to the Philippines.