[al:新概念英语（三）] [ar:MP3 同步字幕版（英音）] [ti:Who's Who] [by:更多学习内容，请到chazidian.com搜索“新概念”] [00:01.44]Lesson 40 [00:03.57]Who's who [00:11.85]How did the policeman discover that the whole thing was a joke? [00:18.59]It has never been explained why university students seem to enjoy practical jokes more than anyone else. [00:26.36]Students specialize in a particular type of practical joke: the hoax. [00:31.94]Inviting the fire brigade to put out a nonexistent fire [00:35.87]is a crude form of deception which no self-respecting student would ever indulde in. [00:41.90]Students often create amusing situations which are funny to everyone except the victims. [00:49.55]When a student recently saw two workmen using a pneumatic drill outside his university, [00:56.51]he immediately telephoned the police [00:58.67]and informed them that two students dressed up as workmen [01:02.33]were tearing up the road with a pneumatic drill. [01:05.59]As soon as he had hung up, he went over to the workmen [01:09.08]and told them that if a policeman ordered them to go away, [01:12.70]they were not to take him seriously. [01:15.42]He added that a student had dressed up as a policeman and was playing all sorts of silly jokes on people. [01:22.15]Both the police and the workmen were grateful to the student for this piece of advance information. [01:28.46]The student hid in an archway nearby where he could watch and hear everything that went on. [01:34.01]Sure enough, a policeman arrived on the scene and politely asked the workmen to go away. [01:40.06]When he received a very rude reply from one of the workmen, [01:43.55]he threatened to remove them by force. [01:46.30]The workmen told him to do as he pleased and the policeman telephoned for help. [01:51.82]Shortly afterwards, 4 more policemen arrived and remonstrated with the workmen. [01:57.77]As the men refused to stop working, the police attempted to seize the pneumatic drill. [02:03.48]The workmen struggled fiercely and one of them lost his temper. [02:07.70]He threatened to call the police. [02:10.29]At this, the police pointed out ironically [02:13.70]that this would hardly be necessary as the men were already under arrest. [02:18.71]Pretending to speak seriously, one of the workmen asked if he might make a telephone call before being taken to the station. [02:26.65]Permission was granted and a policeman accompanied him to a pay phone. [02:31.61]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.