We only know about extinct groups like dinosaurs, ammonites and trilobites through fossils. Some animals and plant are only known to us as fossils. By studying the fossil record we can tell how long life has existed on Earth, and how different plants and animals are related to each other.
Socialists oppose to progressive reform as they think it as revolutionism.
One of the primary ways geography affected early civilizations was in determining the place of settlements.
The answer is cell membrane.
