Tom is seven. He goes to school every day. The school is neat his home. So he goes there on foot and come back home on time. But Today he is late. His mother asks him, why are you late today?

　　I am in the headmasters office. Why do you go to the headmaster office?

　　Because my teacher asks us a question in class, and nobody can answer it, but I can. Its good to answer the teachers questions. But the question is who puts ink on my chair?