A school science club wanted visitors to understand the results of a water-cleaning experiment. The teacher, who had checked the equipment before the exhibition, ① was concerned that a list of numbers would be difficult to interpret. Instead of adding more technical terms, the students prepared short labels. The labels ② attached to each model explained what the group had changed and what it had kept constant. Each label included a question that encouraged visitors to compare two results. The questions that the teacher had helped the students write ③ was placed beside the models. After reading them, visitors could describe the comparison without ④ repeating every number. The club concluded that a useful explanation should make the relationship between conditions visible, rather than require readers ⑤ to remember isolated facts.