Answer:
Transmit and receive audio signals wirelessly over long distances.
Step-by-step explanation:
In the 1920s, radio offered the unique feature of being able to transmit and receive audio signals wirelessly over long distances. This was a revolutionary breakthrough in communication technology, as prior to radio, the only way to transmit audio signals over long distances was through telegraphs or telephone wires, which were limited by their range and required physical infrastructure.
Radio allowed people to listen to live music, news broadcasts, and other forms of entertainment from all over the world, creating a new era of mass communication and popular culture. This made radio a hugely popular invention in the 1920s and beyond, and it played a significant role in shaping modern society and culture.