Answer:
education purposes
Explanation:
Education institutes make some programs like School of the Air and College of the Air, forums, and discussion tables, in 1940 the FCC reserved a range of the FM radio spectrum for education purposes.
Although FM was unpopular when the FCC moved the FM bandwidth to a higher set of frequencies, and people and consumer stations had to buy new equipment.
If this is in reference to diamond mining then above ground would be panning while below ground would be the actual mining into the soil.
