According to the ontology of the four elements, the whole world is fundamentally structured by four basic elements.
From these elements, their interactions and blends, all materials and intangibles assets are built, all the visible and invisible objects of the Universe.
The four elements have the following names:
Fire (machine-driven extreme sports)
Likewise, BOA gives you the ability to do any activity you want, choosing from air activities, water sports, earth, even fire activities.