第24题: [单项选择]The example of the twins going to a university and to a factory separately show ______. A. the importance of their intelligence B. the role of environment on intelligence C. the importance of their positions D. the part that birth plays 参考答案:B 答案解析:最后一段的第三句说明了环境对人的智力所起的作用,所以B正确。