It would be the textbook glossary. A dictionary would be equally useful, but in a science class the teacher would want students to rely on the textbook glossary.
Tom Sawyer convinces Aunt Polly that dreams can hold truth when he told her that he had a dream about the night he went "missing" and she was sitting in her rocking chair and after she fell asleep he kissed her on the head. She later on found out that he was there the whole time and it was not a dream.
When trying to convey the thoughts and feelings of immigrant laborers in the early 20th century, it would be best to read a narrative type of passage, due to the story.
