Synthesized answer
The provided passages do not contain information on how to explain key concepts in my own words. The snippets discuss a legal cross-examination involving a Mr. Braverman and an accident related to work [1]. There is no explanation of "key concepts" or a definition of what those concepts might be.
Synthesized from the book passages below. Chat with the book on Feynman for follow-up.
From the book
Title: The Future of Russia by Braverman, Harry Categories: Soviet Union Pages: 175 Snippet: <b>Braverman</b>, Harry. Wilfred B. Byrne — for plaintiff —Cross . 163 Q. His testimony is that a week after this accident he went back and did some <b>work</b>— ? PLAINTIFF'S COUNSEL : I think Mr. Mowton asked him that question and he denied it . THE ...