Explain three ways that studying seismic waves can scientists learn about earth's interior. enter your answer in the space provided.

By observing how seismic waves are absorbed and refracted, scientist have been able to work out where the properties of the earth change dramatically. our understanding of the internal structures of the earth and the size of its core is based on these observations.

basically:
size of core
structure of the earth I.e. the layers of the earth
and I think the last one is how the internal structure is changing? not sure on the last one but its still a solid guess.

You not be doing this in a quiz. if you actually studied your work you would know the answer. the answer though is that they would use gdp per capita because it measures a smaller portion (person). this could show individual growth per person in the country.