D income hope this is right. if not I'm sorry and plus the rest of the choices did not make sense to me.
The answer would be sound waves.
Hope this helps!
Answer:
National liberalism is a variant of liberalism, combining liberal policies and issues with ... custom unions, subsidies for infant industry or companies considered of national strategic importance and various forms of industrial planning
Agriculture plays a crucial role in the rise and development of civilizations, since it allows for there to be a "food surplus"--meaning that people other than farmers can spend time and effort developing new skills and practicing new trades.
