Puberty in girls begins at 11-12 years, in boys a little later – at 12-13 years. At this time, the proportions of the body change, secondary sexual characteristics appear: in the girls the pelvis expands, the hips round, the mammary glands enlarge, female-type hair growth begins: pubis, axillary cavities; in boys, the growth of the larynx begins, the voice breaks, the growth of the skeleton in the male type begins: a wide shoulder girdle and a slowdown in the growth of the bones of the pelvis. During this period, children grow very quickly and gain weight. So, during this period, growth for the year may increase by 20 centimeters! The size of internal organs increases, blood pressure rises.
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.