The reason why primary school students ask for leave is a humorous joke about grandma's death.

One day, Xiao Ming didn't want to go to school for leave and was lazy at home. Suddenly someone knocked at the door. When she saw that it was Xiaoming's teacher, grandma said, Xiaoming, hide quickly. I said you were ill. Xiao Ming said, Grandma, hide quickly. I said you passed away today. Just then, the teacher met her grandmother at the door. Grandma said, hello, teacher, I am in the seventh grade today. Come back and have a look . .