[___] is when adolescents reach sexual maturity and become capable of [___]. During this time, physical and emotional changes occur and are influenced by the [___] system, which releases hormones into the bloodstream.

The endocrine system releases hormones into the bloodstream, which help regulate the physical and emotional changes of puberty. Puberty is the period when adolescents reach sexual maturity and become capable of reproduction, so the missing system is the endocrine system.

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