The composition of Earth from its surface to its center 6,300 kilometers down can be studied using seismic waves. There are two basic types of seismic waves, S-waves, and P-waves. Students studying Earth's interior are given the following information about P and S waves and how they travel through the earth.
* P-waves at 30 km depth change directions.
* S-waves and P-waves are detected from 5,200 to 6,300 km deep.
* P-waves but no S-waves are detected from 2,900 km to 5,200 km deep.
* S-waves and P-waves are detected from the surface (0 km) to 2,900 km deep.

Using this information and your knowledge of the interior of the Earth, select four statements that are true.