A: Can I borrow your class notes from yesterday's lecture?
B: Heck no! You're so lazy.
A: What are you talking about? I was sick yesterday.
B: I don't care. Ask someone else.
A: You're so mean!
B: I can't let anyone borrow my class notes.
A: Why not? They're just notes.
B: I let a classmate borrow my notes once, and she sold copies to people.
A: That's crazy! For how much?
B: She sold each class note set for $5.
A: Don't worry, I promise not to sell your notes.
B: I can't take your word for it.