What is meant by the phrase "the graying of america"

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Traditionally this term "Greying of America" talks about how the population of America has more older Americans (aka Adults, etc.)  Another way this is said is that the "standard" or "median" age of America is growing.  In general, no matter how this is referenced to/about, when you state this you are stating that the population of America (and/or America itself) is becoming older.

relationship between pressure and air volume and led to the understanding of how respiration works; i believe this is the correct answer ; /// good luck

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