Individual #Kennelly-Heaviside_layer__Heaviside_layer__E_layer__E_region  a region of the ionosphere (from 50 to 90 miles up) that reflects radio waves of medium length
  part of:  ionosphere
  type:  region.location__part  the extended spatial location of something; "the farming regions of France"; "religions in all parts of the world"; "regions of outer space"

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