Complex sentence: The Tai Forest reserve was created in 1926, promoted to National Park status in 1972, recognised as a UNESCO Biosphere Reserve in 1978 and finally added to the list of Natural World Heritage Sites in 1982.
Split into simpler sentences: The Tai Forest reserve was created in 1926 and promoted to National Park status in 1972. It was recognised as a UNESCO Biosphere Reserve in 1978 and added to the list of Natural World Heritage Sites in 1982.