John is nine years old. He is a student of Grade Three. He goes to school from Monday to Friday. But he doesn't go there on Saturday or Sunday. John's school is not far (远) from his home. He walks there. Today he comes back very late. His mother asks him,
"John, why do you come back so late?" John says, "Our teacher is angry. She asks a question (问题) in class. But no one can answer (回答) it except (除了) me. "Then John's mother asks, "What question is it?" John says, "The question is: who puts ink (墨水) on my chair? My answer is: it's me."
