The Earth formed its compositional layers (core, mantle, crust, atmosphere) by accretion in stages: first iron-rich materials, followed by rocky materials, and finally by ices. a. Trueb. False

the roman republic began to expand when rome fought the punic wars and defeated carthage. the punic wars refer to the series of 3 wars fought among rome and carthage, before it ended in carthage's defeat.

within these regions are all the major types of biomes in the world. a biome is a community of animals and plants spreading over an extensive area with a relatively uniform climate. some diverse biomes represented in north america include desert, grassland, tundra, and coral reefs.