How did the policeman discover that the whole thing was a joke?警察是怎么发现这一切其实只是个玩笑的呢？
It has never been explained why university students seem to enjoy practical jokes more than anyone else.一直没有人解释为什么大学生似乎比任何人都更喜欢恶作剧。
Students specialize in a particular type of practical joke: the hoax.学生们专精于一种特定类型的恶作剧——那就是“骗局”（即通过虚假信息或欺骗手段来制造混乱或误导他人）。
Inviting the fire brigade to put out a nonexistent fire is a crude form of deception which no self-respecting student would ever indulge in.请消防队来扑灭不存在的火灾是一种低劣的骗术，任何有自尊的学生都不会染指。
Students often create amusing situations which are funny to everyone except the victims.学生们经常制造一些有趣的、滑稽的情境，但这些情境只有受害者自己觉得不好笑，其他人反而都觉得很好笑。
When a student recently saw two workmen using a pneumatic drill outside his university, he immediately telephoned the police and informed them that two students dressed up as workmen were tearing up the road with a pneumatic drill.最近，一名学生在自己的大学外面看到两名工人正在使用气动钻机。他立即拨打了报警电话，并告诉警方有两名学生装扮成工人。正用气动钻破坏路面。
As soon as he had hung up, he went over to the workmen and told them that if a policeman ordered them to go away, they were not to take him seriously.他一挂断电话，就走到工人们跟前，告诉他们如果警察命令他们离开，他们不应该把他当回事。
He added that a student had dressed up as a policeman and was playing all sorts of silly jokes on people.他还补充说，有个学生打扮成警察的样子，对周围的人开了各种滑稽的玩笑。
Both the police and the workmen were grateful to the student for this piece of advance information.警察和工人们都很感谢这名学生提供的这个消息。
The student hid in an archway nearby where he could watch and hear everything that went on.那个学生躲在附近的一个拱门里，从那里他可以观察到发生的一切，也能听到所有的声音。
Sure enough, a policeman arrived on the scene and politely asked the workmen to go away.果然，一名警察来到了现场，并礼貌地要求工人们离开。
When he received a very rude reply from one of the workmen, he threatened to remove them by force.当他收到其中一名工人的粗鲁回复时，他威胁说要强行将他们赶走。
The workmen told him to do as he pleased and the policeman telephoned for help.工人们让他随意行事，而警察则拨打了求救电话。
Shortly afterwards, 4 more policemen arrived and remonstrated with the workmen.不久，又有4名警察赶到，他们劝告工人们。
As the men refused to stop working, the police attempted to seize the pneumatic drill.由于那些工人拒绝停止工作，警方试图没收那台气动钻机。
The workmen struggled fiercely and one of them lost his temper.工人们激烈反抗，其中一人发火了。
He threatened to call the police.他威胁说要报警。
At this, the police pointed out ironically that this would hardly be necessary as the men were already under arrest.这时，警察讽刺地指出，这实在没必要，因为这些人已经被逮捕了。
Pretending to speak seriously, one of the workmen asked if he might make a telephone call before being taken to the station.装出一副认真的样子，其中一名工人询问是否可以在被带到警察局之前打个电话。
Permission was granted and a policeman accompanied him to a pay phone.获得了许可后，一名警察陪同他前往了一部公用电话。
Only when he saw that the man was actually telephoning the police did he realize that they had all been the victims of a hoax.直到看到那个人真的在报警时，他才意识到他们所有人其实都成了一个骗局的受害者。