A: There's a huge rip here.
B: But there's tape on it!
A: Did you put the tape there?
B: No, it was there before.
A: I know you're lying to me.
B: If you know, then why did you ask if I put the tape on?
A: I wanted to see if you were a liar or not.
B: How did you know I'm lying?
A: Before you check out the book, the librarian checks it for damage.
B: Wow, you guys think of everything.
A: Yes. Anyways, you owe $10.
B: Fine, here you go.