Synthesized answer
The provided passages do not contain information about what questions remain unanswered in "Reflections on Things at Hand." The passages only give the title of the book, the author, the translator, its category as Philosophy, and the total number of pages [Passage 1]. Therefore, it is not possible to answer the question regarding unanswered questions based on the given text.
Synthesized from the book passages below. Chat with the book on Feynman for follow-up.
From the book
Title: Reflections on Things at Hand by Zhu, Xi, Wing-tsit Chan Categories: Philosophy Pages: 441