【明報專訊】"I would give my back teeth to be able to travel somewhere," Petrock said. "It looks to me as though you've lost all chances of going anywhere," Eggmont answered, looking at something on the ground. "Those aren't mine!" Petrock said. "Well, I'd give my back teeth to know who left them there," Eggmont said. This expression means you would make a great sacrifice to do or have something.