3 · Human Being, Man in General
31 · man in a general biological sense
31D · human life and its ages (young, adult, old, etc.)
31D1 · the ages of man
31D11 · the first years ~ the ages of man
31D112 · child
31D1122 · child between toddler and youth (of undetermined sex)
31D11221 · boy (child between toddler and youth)