不明白啊,题干中不是说 Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years,现在被送去治疗的学生比十年前多了么,为什么还选C,现在对化学物质过敏的孩子和十年前相比不太可能送到校医务室,那取非,也没看出来削弱啊? 另外结论中的either...or..不是要么。。要么...的意思么。。。