If you were a fish, how would you obtain oxygen?
Your body cells would break down water molecules (H2O) and release the oxygen.
You would take in oxygen gas dissolved in the water through your gills.
You would inhale oxygen at the surface of the water.
Oxygen would diffuse across your skin.

Question

If you were a fish, how would you obtain oxygen? 
       Your body cells would break down water molecules (H2O) and release the oxygen.
       You would take in oxygen gas dissolved in the water through your gills.
       You would inhale oxygen at the surface of the water.
       Oxygen would diffuse across your skin.

anonymous · Answer

I'm sure you know fish don't breath with lungs :P

anonymous · Answer

In terms of oxygen through skin, it can happen with some living creatures, but the process would be too slow for fish who need energy

anonymous · Answer

Although the body can use oxygen from water to make ATP, it's not the the main source of oxygen

anonymous · Answer

So that leaves you with only one option remaining :)