Ahuman's most rapid growth, both physically _ and _ mentally, occurs between and years old.

The answer is: 0 to 2 years.

Explanation:

From 0 to 2 years, from the moment of the birth of the baby its maximum growth occurs, a normal baby usually weighs about 3.5 kg, and measure around 50 cms. By the fourth month he will have doubled that weight, and by the end of the first year he will have tripled it. This growth, although amazing, is very sensitive to external factors such as feeding or living conditions, although it also depends on the genetic inheritance that the baby has received from its parents.

The answer is: 0 to 2 years.