oxygen is most important use is for breathing
The most important is the oxygen.
The most important gas is oxygen.
The most important are oxygen and carbon dioxide.
oxygen
Respiration
If you didn't have oxygen, you would die!
Oxygen is the most important factor for living things.
carbon oxygen hydrogen nitrogen
Oxygen is more abundant than hydrogen. In fact it is the most abundant element on Earth.
The most important gas is oxygen
Oxygen is itself a chemical element.
I think energy is most important. Blood, oxygen, lungs, and heart is also important...