第13题: [单项选择]The passage is mainly about ______. A. how to keep fit B. how to lose weight C. the benefits brought about by regular exercises D. exercises and diet 参考答案:C 答案解析:文中叙述了regular exercises能保持健康,也能control weight,选项C概括了这两个方面,符合文意。选项A、B不全面,文章不是在论述运动和饮食的关系,选项D也不正确。