I can take this worthless piece of paper, go to the supermarket, give it to a complete stranger whom I've never met before, and get, in exchange, real bananas which I can actually eat.
我可以拿着这张一文不值的纸， 到任何超市， 把它交给一位素昧平生的陌生人， 拿到我可以吃的，真的香蕉。