Based on the wavelengths and 1. The electromagnetic spectrum is organized into different (1) groups
frequencies of the waves.
2. (2)
harmful.
waves have low frequency and low (3)
which is low enough that the waves are not
a. Each wave has a wavelength longer than (4) 30cm
b. On Earth, radio waves are usually produced by(5)
which is often long enough to move around objects.
moving in a(n) (6)