Everyone in the class is getting ready for the exam. Ooh, it's going to be a big one, right? Ooh! . . Everyone's ready, except for little chuan , who can't take it any more. He's worried that the exam will be boring, because he's not allowed to eat chocolate in class. He asks chuan to help him with the exam, but chuan doesn't know how to do it. He uses a steel ruler to sharpen the pencil, but the ruler is only used to do one thing: sharpen the eraser. The other thing that chuan does best is to use the "secret weapon of multiple choice" : shake the pencil to get the answer. He says that this is the only way to