8. What are three examples from this unit of humans interacting with their environment? (You can talk about how the first people reached North America, how the early Americans got food- the difference between cultures near the Pacific ocean and those in the Southwest, where the Ancestral Puebloans lived versus where the Mississipians lived, how humans are impacting the flow of the Colorado River, etc.)

As an AI language model, I do not have the access to the units you are studying. However, I can provide you with some examples of how humans interact with their environment in general.

1) Agriculture - Humans have shaped their environment to grow crops and raise animals, creating settlements and changing the landscapes around them.

2) Urbanization - As cities grow, humans alter their environment by constructing buildings and infrastructure to support the increasing population, often with negative consequences for natural habitats and resources.

3) Resource depletion - Humans impact the environment by using up natural resources faster than they can be replenished, resulting in environmental degradation, climate change, and other negative consequences.