The back of a teacher writing on a classroom blackboard, with students seated below. The teacher is dressed in a neat, professional outfit, with a white shirt and black trousers, and their hand is mid-motion, holding a piece of chalk. The blackboard is filled with handwritten notes and diagrams. The classroom is well-lit with large windows letting in natural sunlight. The students, dressed in school uniforms, are sitting attentively at their desks, some taking notes and others raising their hands. The atmosphere is one of focus and engagement, with the classroom decorated with educational posters and a clock showing mid-morning time.--ar:16:9