Final answer:
Geologists use seismic waves and drilling samples to study Earth's interior.
Step-by-step explanation:
The two main types of evidence that geologists use to study Earth's interior are seismic waves and drilling samples. Seismic waves are generated by earthquakes and can provide information about the composition and structure of the Earth's layers based on how they travel through them.
Drilling samples, obtained by drilling into the Earth's crust, allow geologists to directly analyze the types of rocks and minerals present in different layers.