Consider what the oxygen is spent in seawater.

Oxygen in seawater is consumed for the respiration of living organisms and for the course of chemical reactions (the processes of decomposition of organic substances – decay of dead residues, the formation of substances).

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.