Answer:
The right answers are:
2. analysis of several seismographs
3. location of an earthquake's epicenter
4. identification of seismic wave direction
Explanation:
The Earth’s interior can be studied directly, by using the composition of the rocks, or indirectly, by using seismic waves. Those are the energy that travels across different layers of the earth and have dissimilar behavior when they encounter different states of matter. Their cause can be earthquakes, landslides, etc. Thus and analysis of several seismographs, location of an earthquake's epicenter, identification of seismic wave direction, help to study our planet’s interior.
