托福独立写作段落如何展开？很多考生对于段落的理解定格在了篇幅上，比如一个段落至少5句话、一个段落至少6行等。事实上，尽管段落是句子的“堆砌”，但只有砖头堆砌的墙，成不了真正的建筑。文章的段落也是一样，要一致、连贯地将句与句衔接起来，形成统一的整体。而这个统一体又是有理有据、逻辑清晰，能够让读者一气呵成、顺畅阅读。
因此，无论采取何种段落结构，主体段都应该满足下列要求。
一致：每个主体段中的每一句话都要围绕着一个中心思想(即段落中心句topic sentence中表达的中心思想)。
相关：每个主体段中的每一句话都要与篇章主题相关(即文章主旨thesis statement)。
连贯：每个主体段中的句子要按逻辑顺序排列，符合论证展开的逻辑。充分论证：每个主体段中的各个分论点都要通过摆事实、举例子、列细节等方式充分支持和论证。由于是学术类议论文，原则上文章结构应遵循AREs原则进行展开。
A=assert your controlling idea(usually known as the topic sentence)
R=reason your audience by reasoning(use evidence to explain)
E=exemplify your reasons(provide details or examples and explain the example)
s=summarize your whole paragraph(restate the controlling idea)
这里的s有时也可以省略，但是建议广大考生还是在主体段结束时加上这样的总结，这样既能够显示文章的完整性，也能够检验自己论述到最后是否偏题了，又可以提示读者即考官自己一直在扣题。
考生可以遵循以下步骤，完成段落的展开。
Step 1.构思段落中心思想，撰写段落中心句(topic sentence)
主体段落的展开往往先给出段落中心思想，即段落中心句。该句统领整个段落的发展和论证方向。一个段落中心句，则表达一个分论点，如：
People now are more likely to have diseases than they were in the past.
Step2.解释段落中心思想
段落中心句是否可信，取决于作者是否能够条理清晰、逻辑严谨地向读者解释清楚，如：
As factories develop, environment pollution as a huge issue becomes people's daily topic.It is known to all that factories produce plenty of waste when they are working.Some poisonous gasses like sulfur dioxide would be discharged in the atmosphere and enter people's respiratory system to damage people's lungs and some other organs.Besides, sulfur dioxide,carbon dioxide and other gasses produced by factories are the main components of green house gas, resulting in rising global temperatures,changing people's habitat and making people less comfortable than before.Furthermore, factories also put waste water into rivers and oceans,bringing lots of toxic chemical metal elements such as mercury and lead.Those elements would settle into the soil and be absorbed by plants,then plants are eaten by animals which people feed on.During this process,those toxic elements accumulate in people's body and cause some serious diseases.
Step3.列举事例或细节，并解释分析
分论点的解释有时会过于抽象，难以理解，或给人夸夸其谈的错觉。因此，考生需要提供有利证据，有时是具体的客观事例。考生不要以为罗列了例子就万事大吉，还要给出相应的解释，如：
For example, one of my friends got food poisoning recently, that's because he likes to eat fish, shrimp and other seafood.However, the seafood of the restaurant he usually goes to was polluted because the rate of heavy metal on the fish catching area exceeded the standard level.He was in a lot of and needed to get treatment for two weeks.If people lived in the past, they would hardly have these kind of diseases because factories were not so developed at that time.
Step4.总结段落中心思想，并可以承上启下过渡到下一段落
最后一步是在段落结尾总结以上论述的主要内容，并提醒考官作者在上述段落想要表达的中心思想。如果能够巧妙地预示下一段则更为“有心计”，如：
That is to say, people hardly feel happy for this reason.Unfortunately, this is not the only one to name.
注意，解释和举例的部分可以重复使用。但这当然不是物理重复，而是化学重复，即找到所讨论问题的其他方面，更深入地去讨论，直到作者认为关于这个分论点的几个方面都论述清楚了。如果这样写作，非常考验考生的时间把握能力、思维深度和广度、逻辑严谨性和谋篇布局能力。初学者或目标分数25分以下的考生不建议尝试。
