Answer:
In a group of city-states, each city-state is independent and rules by its own king. No central power controlled all of the city-states. In an empire, consisting of a nation and the city-states and nations it has conquered, one ruler is in control.
Explanation:
This marital practice is called : Endogamy
Endogamy is a marital process in which the grooms and brides only limited from within local community or tribe.
This marital method is deemed to be out-of-date and only carried out in the past to maintain the 'bloodline' of a specific tribe or clan.
The change in breastplates and helmets contribute to decline of the Roman Empire by weakening the the military. It weaken them because the removal of it promote laziness and negligence of training and the such. It also removes the protection against ranged weapons which caused many casualties.
Complex behaviors that are innate, fixed, and universal are called instincts.
Instinct is a fixed response to a certain stimulus, or inclination towards a certain behavior which is universal, meaning that it happens in every organism. Instincts are innate, meaning that you are born with them and cannot learn them.
