Final answer:
Seismographs can provide information about Earth's interior, such as its layers and compositions.
Step-by-step explanation:
Geologists can learn about Earth's interior by studying seismographs. Seismographs are instruments that detect and record seismic waves generated by earthquakes. These waves travel through the Earth's interior and can be measured at different locations. By analyzing the data from seismographs, scientists can learn about the different layers and compositions of Earth's interior, as well as the presence of liquid and solid layers. Seismic studies have shown that Earth's interior consists of several distinct layers with different compositions.