All of Harry's classmates, including Ron and Hermione were sitting in the DADA room, because they were having lesson. Unfortunately, because Lupin is sick, Snape had to take over the lesson. Snape was the class' least favourite teacher. He liked to bully students a lot. With the exception of Slytherins, every student hated him.
Just then, Snape entered the room. Groans emitted through the room. Not just two or three, but a lot. Snape announced, "Turn your book to page 390." The whole class flipped through their book. "TURN IT!" He snarled.
"We already flipped to page 390. Is he crazy or something?" Harry asked Ron, feeling annoyed.
"Yeah, I know right?" said Ron.
Snape continued, "Okay, so can anyone tell me what's the difference between the werewolf and the true wolf?"
"Please, sir," said Hermione, whose hand was still in the air, "the werewolf differs from the true wolf in several small ways. The snout of the werewolf --"
Snape snapped, "Hermione, you insufferable know-it-all. I can't tolerate you speaking out of turn. You are so annoying. Five points from Gryffindor."
Ron laughed, "Haha, I agree. He's got a point you know. Hermione needs to learn how to shut up. She creeps me and Harry out at times."
Harry replied, "I know right, Hermione just shut up!"
Snape said coolly, "Thank you Ron and Harry, you two just contributed to another 5 points of deduction each from Gryffindor."
But Ron or Harry didn't really get angry. They were mad at Hermione, and how she annoys them so much.
After DADA class, Ron said, "For the first time in life, Snape is talking sense." Harry nodded in agreement.