What joke is funny?

The weather is very hot, there are too many people on the bus, so bored that I don't know who farted, and the environment is even worse. My friend can't stand it, and I don't know who it is. I can't help it It happened that the conductor was asking, "Who didn't buy a ticket?" My friend suddenly had a plan and said loudly, "Fart didn't buy a ticket!" " Suddenly, a particularly fat woman, holding the ticket high in her hand, said loudly, "I have bought the ticket!" " "