1-briefly summarized the texts events.
2-how does the repetition show that the narrator's feelings have changed?

1) Daniel Birnbaum went to the principal's office and thought that he did something wrong into realizing he was congratulated for working so hard in the robotics class.

2) The repetition throughout the story was that Daniel thought he'd done something terrible and regretted it as in stated "my heart was pounding in my chest", later he found out he had made the team by saying "I've really done it!"