Answer:
Based on the scientists' observations, it can be concluded that there may be empty caverns deep inside the Earth's crust and also layers of different densities.
Step-by-step explanation:
- The layers beneath the Earth's surface are distinctly dense. Some layers possess very high density, while some are comparatively less dense.
- The seismic waves travel at different speeds through layers of different densities.
- These waves even disappear while penetrating through some layers. This allows scientists to draw solid and reliable conclusions about the formation of the Earth's interior.