Climax
The second thing to regard in choosing passages from books to present before the class is that the lines shall have some point. Conversation in a story is introduced for three different purposes. It illustrates character. It exposes some event of the plot. It merely entertains.
Such conversation as this last is not good material for dramatic delivery. It is hardly more than space filling. The other two kinds are generally excellent in providing the necessary point to which dramatic structure always rises. You have heard it called a climax. So then you should select from books passages which provide climaxes.
One dictionary defines climax: "the highest point of intensity, development, etc.; the culmination; acme; as, he was then at the climax of his fortunes." In a play it is that turning-point towards which all events have been leading, and from which all following events spring.
Many people believe that all climaxes are points of great excitement and noise. This is not so. Countless turning-points in stirring and terrible times have been in moments of silence and calm. Around them may have been intense suspense, grave fear, tremendous issues, but the turning-point itself may have been passed in deliberation and quiet.