city-states are larger and were governed independently unlike cities
true
one is faster than the other
That depends entirely upon the town/city in question. A New York City block is a different length than a Chicago block; a New York City or Chicago block is a different length than a Jackson, Mississippi block, and so on. Please ask your question again, this time specifying a town or city.
The river near large city contains pollutants.
True.
Yes she had 2 in different city's and dated them at the same time
No, Copehagen is the Capitol city of Denmark. Denmark is a different country than the Netherlands.
It depends on what city you are in. The contact information to hire a city cab in San Francisco is going to be different than the contact information for a cab in New York City.
Lego City is a completely different theme than Lego Star Wars, and therefore is not in the same game.
it included a number of independent city-states with competing rulers
It depends on the context of the word.If you are talking about more than one city (plural) then you would use cities."I have lived in four different cities."If you are talking about possession then you would use city's."The city's mayor is my cousin."
The Outsiders had an impact on me, the impact was that people aren't really all that different even if they are from the different sides of the city or they are richer or poorer than me.