实例: 据说有这么一回事:太平洋的某一个岛屿,有一天一前一后来了两个分别属于两个国家的两个皮鞋厂的推销员。他们都在岛上逛了一圈,都对岛上的商品市场作了一番调查了解。第二天,这两个推销员各自都给厂里发回了电报。先到的那个推销员发回的电文是:“此岛无人穿鞋,皮鞋无销售市场,我于明天返回。”后到的那个推销员发回的电文是:“此岛无人穿鞋,皮鞋销售前景很好,我将在此住一段时间。”第三 Example: It is said that there is one thing: an island in the Pacific Ocean, one day after another, two salesmen from two shoe factories belonging to two countries. They all walked around on the island and made a survey of the island’s commodity markets. The next day, the two salesmen each sent a telegram back to the factory. The message sent by the first salesman was: “No one wears shoes on this island, and there is no market for leather shoes. I will return tomorrow.” The message sent back by the salesman is: “No one wears shoes on this island. The sales prospects of leather shoes are very good. I will stay here for some time." Third