Answer:
D because the definition says so
Because they once thought it was flat. But some scientist thought that the moon was smaller than the Earth and they needed to find out.
Stalin didnt trust anyone, converting the society into being swarmed by its now, totalitarian government. everyone was being watched at all times, and if anyone was being caught saying something unappealing about their leader or nation, they would disappear. it was motivated among the neighborhoods to out those speaking ill as well, this made a once rowdy and lively nation become more private and suspicious as a whole
to raise awareness and try to bring different ideas into the world/society. Also to communicate with indivisuals.