Question

three things have to be present for the transmission and receptions of sound
□ medium
□ source
□ detector
□ antenna
□ vibrating ear
□ brain

Explanation:

To transmit and receive sound, we need a sound source (produces sound), a medium (transmits sound waves, like air), and a detector (receives sound, like an ear or a microphone). "Vibrating ear" is incorrect (ear detects, not vibrate as source), "antenna" is for EM waves, "brain" processes, not receive/transmit sound. So the correct ones are source, medium, detector.

Answer:

• source
• medium
• detector