(背景)教室・教壇・黒板：(Background) Classroom, teacher's desk, blackboard

classroom interior, daytime, bright noon sunlight streaming through tall windows. Viewed from the front of the room. A large green chalkboard dominates the front wall with faint chalk residue and partial equations from a previous lesson. A wooden teacher's podium stands before the board holding stacked textbooks and a piece of chalk on the ledge. Rows of empty wooden desks and chairs face forward across the floor. Dust motes drift in the warm sunbeams. Fresh, cheerful midday atmosphere.