1. Students specialize in a particular type of practical joke: the hoax.
    大学生擅长一种特殊的恶作剧--戏弄人。

2. 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.
    当他看到那个工人真的是给警察挂电话，才恍然大悟，原来他们都成一场骗局的受害者。