He Zhouji

The teacher gave four students 5 yuan and asked them to buy something to fill the classroom. Student A bought straw and the classroom was not filled. Student B bought sand and soil, but the classroom was far from full. Student C bought candles, but there were always shadows in the classroom. At this time, classmate Ding bought a bowl of porridge cooked with nuclear sewage. Suddenly, nuclear radiation filled the entire classroom.