Stories about keeping pupils' families tidy.

After retirement, an old professor toured schools in remote mountainous areas to share his teaching experience with local teachers. Because of his friendliness and affability, the old professor is welcomed by teachers and students all over the world.

Once, after visiting a school in a mountainous area, he wanted to go to another place. Many students were reluctant to go, and the old professor could not help but be moved. At present, he promised the students that the old professor would give them a mysterious gift as long as someone can clean up their desks and chairs next time.

After the old professor left, every Wednesday morning, all the students have to clean up their desks, because every Wednesday is the day when the professor will visit every month, but I'm not sure which Wednesday the professor will come. One of the students has a different idea from the others. He wants to get a gift from the professor as a souvenir, because he is afraid that the professor will suddenly come with a mysterious gift on a day other than Wednesday, so he has to tidy up his desk and chair every morning.

However, the desktop cleaned in the morning is messy in the afternoon. The students were worried that the professor would come in the afternoon, so they cleaned it again in the afternoon. I feel uneasy when I think about it If the professor shows up in the classroom an hour later, he will still see his desk in a mess, so he decides to clean it every hour.

Finally, he thought that if the professor came at any time, he might see that his desk was untidy. Finally, the pupils thought clearly that he must always keep the desktop clean and welcome the professor at any time.

Although the old professor didn't show up with a mysterious gift, the student got another strange gift.