Final answer:
Childhood, adolescence, and old age are unique to people because each phase of life comes with different responsibilities, expectations, and changes in physical, cognitive, and social development. During childhood, individuals experience rapid growth and development, learning new skills and exploring the world. Adolescence is a period of transition from childhood to adulthood, marked by physical maturation, the development of personal identity, and changes in relationships. Old age is a time when individuals may experience physical declines but also have the opportunity to enjoy life without as many work and family pressures.
Step-by-step explanation:
Childhood, adolescence, and old age are unique to people because each phase of life comes with different responsibilities, expectations, and changes in physical, cognitive, and social development. During childhood, individuals experience rapid growth and development, learning new skills and exploring the world. Adolescence is a period of transition from childhood to adulthood, marked by physical maturation, the development of personal identity, and changes in relationships. Old age is a time when individuals may experience physical declines but also have the opportunity to enjoy life without as many work and family pressures.