What was one of the similarities of the Maya's, the Incas, and the Aztecs?

Not sure actually why do teachers expect us to know so much

There are many similarities but I have listed one below.

All 3 pre-columbian major civilizations the mayam the Maya, the Aztec, and the Inca were all without the one thing that we always see in early civilizations. It's a geographic feature which is a river. So there was no rivers. That in itself was very odd and rarely do civilizations develop without rivers.