¿Porque Europa tiene un relieve de escasa altitud?​

One of the main reasons societies settled along rivers in the neolithic era was because a) the village elders demanded it. b) the land there was more valuable. c) it was more safe and secure there. d) it provided irrigation for farming.

Which two following best identify the central themes of this speech in the passage the man in the arena

What is the thickest layer of earth called?