(Penny shows up at Leonard's door)
Leonard: Oh hey, I haven't heard from you in a couple days, are you still mad at me?
Penny: Nope. I have no reason to... (holds up her paper) "B" mad at you. Minus!
Penny: That's right, on my paper, not yours, mine, you punk-ass elf!
Leonard: I don't know what to say.
Penny: How about (mocking Leonard) "gee, Penny, you're smarter than I thought. You may be the one in school but I'm the one who learned a lesson. I'm so stupid, Penny, DUUUHHHHHH!" (walks away)
Sheldon: (laughing) She sounds exactly like you!