Answer:
From my point of view, I would say Jurors 3, 10, and 12 are most stubborn because, juror 3 is so dogmatic, juror 10 is somewhat like a bigot and 12 is just business man who sees everything ambiguously.
"Mighty” reflects how powerful and influential the speeches were to Douglass in a way that “great” would not.
<em>Mighty</em> means possessing power or authority. These elements are not exactly part of the definition of the word <em>great</em>, which simply means large, remarkable, or predominant. With <em>mighty</em>, there is a connotation of significance and impact. Indeed, the narrator tells us that these speeches fascinated him ("unabated interest") and influenced his thinking ("they gave tongue to interesting thoughts of my own soul").
A participant in a group discussion can be an effective speaker by remaining concise and speaking on the same level as the other participants so as not to confuse them. The participants can also ask for feedback and ask if they need to clarify anything so the listeners are able to get the most out of the discussion. A speaker should also always come prepared and bringing notes and guidelines. I hope I helped!