Question

earthquake waves move at different speeds in different materials. therefore we can determine the composition of what part of earth using earthquake waves? earths atmosphere earths layers

Explanation:

Earthquake waves (seismic waves) interact with different materials in Earth's interior. By studying how these waves speed up, slow down, or reflect/refract as they pass through different regions, scientists can infer the composition and structure of Earth's internal layers (like crust, mantle, core). The atmosphere is gaseous and seismic waves don't travel through it in the way relevant for studying composition in the context of Earth's internal structure. So the correct option is related to Earth's Layers.

Answer:

Earth's Layers