Responses
O2, not H2O. H2O is water.
plants make a large portion of the oxygen available on earth but there's other ways that oxygen is synthesized naturally and experimentally. the internet is there if you wanna learn but the simplest example would be oxygen canisters that they use in hospitals. how do you think they get that? from a greenhouse?
I wonder how they survived with no plants? I mean humans need H2O to survive right? So if plants are extinct,why are they still alive?