A 段( introduce the topic/problem )
首句开门见山引出文章主题： Playing is a serious business. 后面的句子主语都是具体名词( children, fox )不用看。而后出现指示性词语 but ，后面内容说明很重要。“ For a start, play can cost animals their lives. ”就引出关于“玩”的问题所在EuE.既然玩可能会付出生命的代价,说明它确实很严肃,那么玩到底能给动物带来些什么呢,这就是问题所在了.下面出现数字具体名词等都是细节，不用看。
B 段 (literature review)
首句设问，自问自答，答案在第二句。 The latest idea suggests that play has evolved to build big brains. In other words, playing makes you intelligent.
这句话就是段落主旨句，既然文章要论证玩是严肃的事，所以这里就搬出最新理论说明玩和智力发展的关系。
C,D 段( Comment on the previous theories )
C ， D 两段主要承接 B 段提出的理论进行分析批判
C 段：批判 Exercise theory
首句： Take the exercise theory.
D 段：批判 Skill-training hypothesis
首句： Then there’s the skill-training hypothesis.
通过 C ， D 两段尾句可以发现玩和身体健康以及培养技能没有必然的联系，故下文内容大致可以推断为作者提出他自己的看法。
E 段( writer’s approach )
作者认为玩直接和大脑有关，从首句从句内容即可发现： There is a strong positive link between brain size and playfulness among mammals in general.
F ， G ， H 段都应该是 supporting evidences
F 段( supporting evidence 1: the timing of play and brain )
首句 the timing of the playful stage in young animals provides an important clue to what’s going on.
记住文章的论述的主题是玩和大脑的关系，所以这句话就意在揭示玩的时间段和大脑的关系。通过尾句我们可以找到这种联系： I concluded it’s to do with learning and with the importance of environmental data to the brain during development.
玩的时间决定着大脑发展中环境数据的输入。
G 段( supporting evidence 2: Play and the activated areas of brain )
首句： People have not paid enough attention to the amount of the brain activated by play
玩能激起大脑很多部分的开发。
H 段 (Supporting Evidence 3: play and higher cognitive process)
首句： …but it also seems to activate higher cognitive process.
玩还能激发高级的认知能力
I 段(展望未来)
