The Dangers of Miscommunication by Jack Ichijouji
After Colin had scampered off to find his lady love (feeling slightly put-out by Ginny's fun) Ginny returned her attention to Niptuck the Medical. The essay was easy to write once she got going. She wrote one paragraph and the reworded it again and again until she filled the length of the essay. She got the idea from Binns' lectures, which worked in a very similar fashion.
She looked up from her essay to find Harry standing nearby, wearing a very strange look on his face. "Harry, glad you're here. I'm down to the last paragraph of this thing and I'm running out of synonyms. How do you spell 'knockers'?"