A

 Hugh Troy, a well-known artist, was a very interesting and clever person who spent most of his life playing tricks (恶作剧) for the joy of it．

 One winter in the 1920s, while a student at Cornell University in Ithaca, New York, Troy got hold of a very old and ugly waste basket with a real rhinoceros (犀牛) foot as its base． He filled it with metal weights and tied 30 feet of clothes, line to either side． Late one night he and a friend carried it out onto campus, pulling the lines straight between them． Every few feet they would lower it into the snow, their own footprints so far as to raise no suspicions (怀疑)．