Complex sentence: In 1999, the Maasai Giraffe and White Rhinoceros exhibits were opened, followed by a Nile hippopotamus exhibit in 2002 where visitors can view the animals both above and below the waterline.
Split into simpler sentences: In 1999, the Maasai Giraffe and White Rhinoceros exhibits opened. These were followed by a Nile hippopotamus exhibit in 2002 where visitors can view the animals both above and below the waterline.