Answer:
D
Explanation:
It takes 3 different vibrations to hear a sound, since sound is made when things vibrate (or wiggle) : The object that makes the noise vibrates (our bell). The air molecules vibrate as the sound moves through the air. The eardrum vibrates when the sound wave reaches it
Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.
