What periods can be divided into human development from 1 to 21 years?

The period of childhood lasts from 1 to 12 years, at this time the development of milk, and then permanent teeth, active growth and weight gain, mastery of speech, reading, writing. At the age of 12-16, sexual development occurs, secondary sexual characteristics are formed, by the age of 21, the development of all organ systems is completed.

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.