Final answer:
Children between 6 and 9 months old achieve milestones in object permanence, verbal response, and language development.
Explanation:
Object permanence: Children around 8 months old start grasping the concept that objects exist even when not in sight.
Response to verbal requests: Infants between 9-12 months can follow simple commands like waving bye-bye or blowing a kiss.
Language development: Infants start naming objects by about 6 months and use common words by 10-12 months.
Learn more about Cognitive development in infants here:
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