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

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.

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