The best answer is minority groups (racial groups would work too, but only if physical characteristics are mentioned, but not for cultural practices).
Minority groups are often discriminated: treated unfairly.
At first he was going along with the encomienda systems but then after a while he drooped all his slaves and ect and thought that they deserved their rights and so he began fighting for them.
City-states were powerful cities in italy and surrounding towns and country side. they are governed independently
In most urban areas, it is very common that there is a lot of pollution as a result of all the cars and pollutant producing things like vehicles. Thus making it quite a problem as it can have many health implications (if on a large scaled (see cities like China where people have had to wear masks to prevent any toxication)). Pollution also contributes to global warming which is an ongoing issue that affects the entire world.
