<span>I think the right answer is "which they reach a certain age." Jean Piaget is a psychologist who studied human development. According to his theory, human development is divided into stages, these stages are achieved due to cognitive maturation during the first years of life. <span>Each stage of development is characterized by more specialized skills, behaviors, and cognitive skills.
I hope my answer can help you.
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Answer:
the Appalachian Mountains
Explanation:
It’s obviously traditional so your answer is C
