Answer: Dialogue that reveals personalities.
Step-by-step explanation:
The Miracle Worker is a play written by William Gibson. It tells a story about a blind and deaf girl, Helen, and her attempt to learn how to communicate with others.
This excerpt is a dialog between Annie, a woman that is teaching Helen sign language, and Annie's own teacher, Anagnos, who taught her how to read and write. Anagnos is also the director of the Perkins Institute for the Blind. The dialog reveals certain aspects of their personalities, and tells us a lot about their relationship. It is through the dialogues between the characters that an author presents their personalities to the audience.