Ok I’m Which was the main way the incas modified their environment to grow more food ?

The main way that the Incas modified their environment was that they built cisterns and irrigation canals

Explanation:

They developed resilient breeds of crops such as potatoes, quinoa, and corn. They built cisterns and irrigation canals that snaked and angled down and around the mountains. And they cut terraces into the hillsides, progressively steeper, from the valleys up the slopes.

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answer: a federal government has final authority on interstate/inter provincial  and international affairs, a confederation is one where the central/national government or authority is governing body what does not have final say over the same matters. hopefully this and i will try again if you don't like this answer : )

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