Before I came to Princeton University, I heard that there was a strange door with a magic spell - "If any Princeton students dared to cross this door before graduation, they would not graduate normally. I'm sure I'll look for that door. It turned out that the door was next to Nassau Hall, called FitzRandolph FitzRandolph Gate. Strangely, I couldn't locate it on Google 160; map. I see a lot of people wantonly crossing this door, and those people don't look like tourists, so I guess there are still a lot of Princeton students who don't believe in evil to challenge, but whether they can graduate or not, I don't know.