Why do the layers get increasingly more compact as you move closer to the center of the Earth?

When lactate builds up in a runners muscles it causes a burning sensation what causes this to occur

Which statement names a physical property of wood? wood does not rustwood can burnwood can rotwood is softer than coal

The frequency of alleles in a population that is in hardy weinberg equilibrium? a . changes in each successive generation b. is less important than the frequency genotypes c. shows evidence of the process of natural selection d. remains the same over several generations