What is the main topic of the passage? A. The changing pollutants in the atmosphere. B. The decreasing pollution of the atmosphere. C. Hydroxyl’s influence on the atmosphere. D. The oxygenaĐoạn văn57/96What is the main topic of the passage? The changing pollutants in the atmosphere. The decreasing pollution of the atmosphere. Hydroxyl’s influence on the atmosphere. The oxygenation of the atmosphere.Giải thíchChọn A