Will it be possible for us to breathe underwater with something much smaller than apparatus?

Question

(in the future)

Answer 1

Not likely. The fact is that, as warm blooded animals, our oxygen demand is higher than the amount of oxygen that is dissolved in a lungful of water. To be able to survive with the amount of oxygen dissolved in water alone would require much more effective oxygen utilization or much reduced demand. The brain already consumes about 20% of everything the human body uses, and any reduction in the demand would require smaller (and thus less smart) brains.

Answer 2

no way girl! do not even try to breath under water neverrr!!!