Complex sentence: The Australian branch of Humane Society International (HSI) was launched in 1994 at a ceremony attended by Senator Bob Brown and the President of HSUS, John Hoyt, who was the master of ceremonies at the event.
Split into simpler sentences: The Australian branch of Humane Society International (HSI) was launched in 1994. At the launching ceremony of the HSI, Senator Bob Brown and the President of HSUS, John Hoyt were at the event.