Final answer:
The provided excerpts do not contain information about Serafina and Nadia's situation at the parade. Without clear context, we cannot deduce why Serafina doesn't wave back at Nadia.
Step-by-step explanation:
The main reason Serafina does not wave back at Nadia at the parade is not explicitly stated in the excerpts provided. In literature, characters' actions and motivations can often be determined by the context of their relationships and the narratives surrounding them, which might involve emotions like resentment, preoccupation, or social dynamics like envy or misunderstanding. However, without a specific reference to Serafina and Nadia’s situation, we cannot confidently provide an explanation based on the given examples.
These excerpts describe various characters and scenes that involve a lack of communication or response among individuals, and while they can serve to illustrate potential emotional or social reasons why someone might not respond to a gesture like waving, they do not directly answer the question about Serafina and Nadia.