Synthesized answer
The provided passages do not contain the answer to what questions remain unanswered in Plato's *Phaedo*. The passages mention the title of the book, its author, and its category as "Immortality," as well as its page count [326]. However, they do not offer any details about the specific content of the dialogue or any questions that are left unresolved.
Synthesized from the book passages below. Chat with the book on Feynman for follow-up.
From the book
Title: The Apology, Phaedo and Crito of Plato; Golden Sayings of Epictetus; Meditations of Marcus Aurelius by Charles William Eliot, Πλάτων, Epictetus --- Google Books --- Title: Plato's Phaedo by Plato Categories: Immortality Pages: 326