The answer is: Cities
Approximately, around 80% of united states population live in the cities. This happen because most of job opportunities that exist in united states (whether it's art, technology, or manufacturing) are located in the cities.
Because of this, even people who born in rural areas start to move to inner cities in order to find jobs and sustain their living.
Answer:
Biosafety level 3 requires at least two-door separation between the area where biohazards are used and the personnel not associated with the research, requires inward inflow into the lab and must have a visual mechanism to verify that air is flowing in the appropriate direction
Explanation:
Biosafety level 3 is required for clinical, diagnostic, teaching, researching or production laboratories working with microbes that are also following BSL-1 and BSL-2 but as these pathogenic agent can lead to life-threatening disease by inhaling it, besides other contaiment precautions, the BSL-3 facilities must have a separated entrance to laboratory door with unrestricted traffic flow and the lab must be behind two sets of self-closing doors and windows must be sealed, with a ventilation system properly directioned installed.
Rejuvenated traditional crops and farm practices.
