(一)有两个哲学家和两个数学家去参加一个学术会议,数学家发现两个哲学家只买了一张火车票,很讷闷,不知道火车上查票怎么办?火车上开始查票了,数学家发现两个哲学家一块进了卫生间,没多久,列车员开始敲卫生间的门,门开了一个缝,里面递出一张票,然后关上了门,列车员看了看票,敲 (a) There were two philosophers and two mathematicians attending an academic conference. The mathematician found that the two philosophers only bought a train ticket. It was very boring. They did not know what to do on the train. The train began. After checking the votes, the mathematician discovered that two philosophers entered the bathroom one after another. Soon after, the conductor started to knock on the door of the bathroom. The door opened a seam, and a ticket was handed out. Then the door was closed and the conductor looked at the ticket. knock