第4题: [单项选择]The main purpose of this passage is to ______. A. encourage people to run B. describe a popular activity C. make fun of runners in costume D. give reasons for the popularity of footraces 参考答案:B 答案解析:本文概括性地叙述了一项受人们喜爱的体育活动—赛跑。第一段主要介绍此项活动的益处,参赛者的年龄、目的、地点和距离。第二段具体描绘某些比赛场面。故答案选B。