A barrier in which a concept is only thought of in its most typical form is called

Baby Manny discovered how to use a stick to get toys that were out of reach. According to Piaget, Manny's behavior would best be described as a

A) tertiary circular reaction. B) secondary circular reaction. C) primary circular reaction. D) reflexive scheme.

Each year, almost ____________ U.S. teenage girls become pregnant

A) 750,000 B) 50,000 C) 2,000,000 D) 120,000