solids only. liquids only. gas, liquids, and solids. gas and a vacuum only.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A longitudinal wave, such as a sound wave, can travel through
Possibilities:
- solids only.
- liquids only.
- gas, liquids, and solids.
- gas and a vacuum only.

gas, liquids, and solids.