第2题: [单项选择]The children who were selected for the experiment gained more IQ points than the others because they were ______. A. more clever B. taught by different teachers C. taught with new materials and methods D. given more encouragement by their teachers 参考答案:D 答案解析:推理题。根据文中“Teachers…had given them more positive reinforcement.”(教师给了他们更多的正面帮助。) positive reinforcemen