Answer:
C. The greater an element's density, the smaller the amount of it found in the crust
Explanation:
The layering of the Earth happened because of the different densities of the elements from which it was made. The denser elements started to sink deeper, the elements with medium density occupied the central part, and the elements with the smallest density remained at the surface. This resulted in the formation of the three basic layers of the Earth, core, mantle and crust. The core is composed of the densest elements, the mantle of the ones with medium density, and the crust from the ones with smallest density.
Deindustrialisation which resulted in less factories as companies shifted their manufacturing operations to countries of lower production cost. This results in less pollution to the environment as the industrial scene is replaced by the growing services sector. The increasing emphasis on human development and henceforth the sustainability of development is also a contributing factor.
all of the above d because all can be from animals
I know that Boston is a main port of the American Economics, so they would want it for exporting and importing goods. I would assume that Philadelphia would have a related cause.
They could adapt to live together so that for example one starts eating only seaweed while the other starts eating only organic matter so they don't compete for food. They could also adapt like when squirrels are separated into those who eat on trees and those who eat on the ground. The 2 urchin types could split into those who eat of the ground and those that eat what floats and drifts.
