How do seismic waves help scientists understand Earth's layers select the two correct answers

Question

Scientists can observe how seismic waves change speeds when passing through different layers
Scientists can observe which seismic waves cannot pass through the certain layers
Scientists can observe how seismic waves multiply when passing through different layers
Scientist can observe which seismic waves change the composition of the layers they pass through
Scientists can generate seismic waves in order to observe their path through Earth

Answer 1

The two correct answers are:

1. Scientists can observe how seismic waves change speeds when passing through different layers.
2. Scientists can observe which seismic waves cannot pass through certain layers.

These observations help scientists understand the properties and composition of the Earth's layers based on how seismic waves behave as they travel through different materials.