system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are humans and most other species dependant on water? Is it just coincidence that 70% of earth is covered in it?
gpt
We need a liquid that can act as a medium for our bodies to do all the important things it does. 

Water is an easily accessible one that is made up of two commonly found atoms. It's electrically neutral, non corrosive/toxic/flammable and doesn't react with a lot of stuffs. It's melting and boiling temperature range is just right to not damage the structure of cells at the distance that the Earth is from the sun. 

There is no other liquid that fulfills all of the aforementioned criteria.