The lecture efficiently casts doubt on the three theories of the utilizes of the Chaco Canyon, proposed by the reading, demonstrating that none of these are convincing.
To begin with, the reading offers the theory that the Chaco structures are purely residential, which contradicts what the lecture maintains. The lecture holds that, although the outside of the Chaco appears for residence, the lack of fireplaces inside of them proves not suitable for dwelling. There are supposed to conclude 100 people living, while the largest fireplaces found can only support ten, not mention the lack of rooms.
Second, the reading believes that the Chaco might be used to store food, like maize. However, the lecture disagrees with it by saying no maize traces were found in the Chaco. To hold a large amount of maize, large containers were needed, whereas no containers are uncovered in the Chaco.
Finally, the passage assumes the Chico served as the ceremonial center, contradicting the opinion from the lecture. The speaker presumes that, as materials for construction like sands, stones, except some broken pots, were found around the Chico, the possibility of holding a ceremony is little. The pots might be the trash that construction workers discarded after finishing their work.