1) The national animal of Australia is the kangaroo.

2) Celtic mythology encompasses the folklore and legends of the Celtic peoples across Europe, particularly in regions like Ireland, Scotland, and Wales. It features deities like Morrigan, Cernunnos, and Brigid, and delves into themes of nature, magic, and the heroic exploits of legendary figures like Cu Chulainn.

3) The process of photosynthesis, performed by plants, algae, and some bacteria, is responsible for producing the oxygen we breathe.

4) The painting "The Scream" by Edvard Munch is an iconic work of art that depicts a figure in anguish and has become a symbol of existential angst.