Answer: the relative differences in arrival times of the S and P seismic waves at several recording stations tell scientists about the different speeds those waves were traveling at, which in turn gives information about the density of the material the layer is made of, and how thick the layer is in several directions.
Explanation:Earth's layers
Answer:
I could be wrong but I believe it is,
"rocks," and "dark matter"
False; everything in your body is made up of cells.
