Signals from this portion of the electromagnetic spectrum may be characterized by their dispersion measure. VLBI was developed to study (10[1])this portion of the electromagnetic spectrum, in which Jocelyn (10[1])Bell Burnell discovered LGM-1. The 21-centimeter line (10[1])in this frequency range can be measured through cosmic dust. The highest angular resolutions are achieved by astronomical interferometers (-5[1])that measure radiation from this frequency range. Puerto Rico’s Arecibo Telescope (10[1])was built to study radiation from this frequency range, which provides the name for quasars and pulsars. For 10 points, name this longest-wavelength portion of the electromagnetic spectrum, commonly used for broadcasting. ■END■ (10[1])