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.
<span>If a person does not have sufficient knowledge for designing an effective exercise program, it is likely this person will abandon it. True</span>