Extremities of the digging type in the mole, limbs of the swimming type in the otter. Chimpanzees are characterized by grabbing limbs. In a reindeer that travels long distances in search of food, running limbs, etc. All of these types of limbs are homologous organs, since they have a similar structural plan, and the observed differences are phenotypic.
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.