Answer:
Cities, Military and Social Classes are the correct answers.
Step-by-step explanation:
A civilisation is a complex culture in which large number of people share common elements. Historians identify six of the most important characteristic of a civilisation: Government, Religion, social Structure, writing, art and Cities. The first civilisations developed in the river valleys as they could support large scale farming that was necessary for feeding a large population of people. New patterns of living(Cities) emerged once food became abundant. The growth of population required government to maintain food supply and protection. Governments organised and regulated human activity, the first governments were led by monarchs. Kings and queens used to rule the kingdoms and organised armies for protecting their people and made laws for regulating peoples lives.