The diver uses an air tank, which is a tank filled with compressed air. It has a hose that goes from the tank to the mouth, which is held in the mouth by a 'mouth piece'. The tank has a regulator that allows the pressure in the tank to be regulated down for normal breathing.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.