Mark Twain, as you know, was famous in his day as a public speaker. In his public speeches

, he not only liked to tell funny stories, but also liked to play jokes on his friends.

One day, at a railway station, one of his friends lost his wallet and asked Mark Twain to pay the train fare for him.

"Sorry, I don't have enough money to pay both your fare and mine." Mark Twain said The friend did not know what to do.

"We can do this. "Mark Twain said after a while, "You can get on the train and when the conductor comes to check the tickets, you can hide under my seat."

Later, however, when the conductor came to check the tickets, Mark Twain gave him two tickets--one for his friend and the other for himself. Then he explained in a loud voice, "My friend here is a strange man. When he travels in the train, he does not like to set on the seat. He prefers to lie on the floor under the seat. "Of course, everyone in the compartment (车厢)looked at the poor man under the seat mid laughed at him loudly.

This passage is about ______.

A．why Mark Twain refused to buy a ticket for his friend

B．how Mark Twain and his friend traveled on the train

C．how Mark Twain's friend lost his wallet

D．a joke Mark Twain played on one of his friends