Complex sentence: Sim was educated at Raffles Girls' School and Hwa Chong Junior College, before going on to on to Oxford University where she completed a degree in Philosophy, Politics & Economics in 1997.
Split into simpler sentences: Sim was educated at Raffles Girls' School and Hwa Chong Junior College. She then went on to Oxford University, where she completed a degree in Philosophy, Politics & Economics in 1997.