So that the biosphere does not cease to exist and so that its development does not stop, the circulation of biologically important substances must constantly take place on Earth, This means that after use they must again go into a form suitable for assimilation by other organisms. This transition of biologically important elements from link to link, which is carried out on the scale of the entire planet at a certain cost of energy, the source of which is the Sun, is called a geological, or large, cycle.
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.