智
文章中的分段落的主题句如何写，以及论证方法之一：解释法。今天为大家分析下第二大论证方法——因果法。
因果法用于topic sentence和中间的supporting details都可以，首先我们来看一看综合作文中是如何运用的。
一、对于topic sentence
1. TPO 篇topic sentence:
The shortened workweek would increase company profits because employees would feel more rested and alert, and as a result, they would make fewer costly errors in their work. (缩短的周工作日可以提高公司的利润，因为员工可以感觉到更多的休整并且机警了，结果就是他们工作上犯错率减少了。)
For the country as a whole, one of the primary benefits of offering this option to employees is that it would reduce unemployment rates. (对于整个国家来说，因为可以减少失业率，所以缩短周工作日是个好事。)
分析：这是一篇TPO中的两个分topic sentence, 不难看出都用了一个因果逻辑，那为什么写topic sentence要用因果法呢?我们再来回顾一下topic sentence的要求：每个分topic sentence都是要求能够论证总的topic sentence的，比如说：总论点是赞同广告的好大于坏，分论点是广告的好处之一是通过能够给消费者提供信息，从而能够帮助消费者购买到合适的产品，那么为了能证明是好处，就一定会写结果带来什么好处，因此因果法在写分topic sentence的时候会大量使用。再回到这个两个topic sentence中就不难发现，为了说明缩短的工作日带来更多的好处，我们要说带来好处的原因(更多休整)或是结果(犯错率少)，因果法就恰到好处地写到了这一点。
2. TPO 第六篇topic sentence:
First, contributors to a communal online encyclopedia often lack academic credentials, thereby making their contributions partially informed at best and downright inaccurate in many cases. (首先，网上百科全书的贡献者通常缺少学术认证资质，因此使得他们的贡献最多部分正确，或者许多情况下完全不正确。)
Third, the communal encyclopedias focus too frequently, and in too great a depth, on trivial and popular topics, which creates a false impression of what is important and what is not. (第三，网上百科全书太频繁、太深入地关注很琐碎、很流行的话题，因此给人们产生了一种不知道哪些重要哪些不重要的错误概念。)
分析：从这篇的topic sentence中也不难发现作者为了证明网上百科全书的问题，在写分论点句时，作者直接写出了因为网上百科全书的缺陷(贡献者缺少学术能力，关注得太琐碎等)导致了种种问题(内容不准确，没有重点等)，用了因果逻辑完成了topic sentence。
总结：独立作文当中，大家可以适当用因果法写写topic sentence，这样能够准确地论证总论点。
二、对于supporting details
1. TPO 第七篇 主体段：
First, American consumers are exposed to so much advertising that they would not value or even pay attention to the ecocertification label. Because so many mediocre products are labeled “new” or “improved”, American consumers do not place much trust in advertising claims in general.
(首先，美国顾客目前接触到太多的广告，因此他们不会再珍惜或注意到这个生态认证标识，因为有太多的中庸产品被贴上了“新的”或者“改善的”标识，美国顾客就不太信任广告所声称的内容。)
Second, ecocertified wood will be more expensive than uncertified wood because in order to earn ecocertification, a wood company must pay to have its business examined by a certification agency. This additional cost gets passed on to consumers-American consumers tend to be strongly motivated by price, and therefore they are likely to choose cheaper uncertified wood products. Accordingly, American wood companies will prefer to keep their prices low rather than obtain ecocertification.
(其次，生态认证的木头比非生态认证的木头更贵，因为为了获取这样一个认证，木材公司要付费给证书代理检验费用。这额外的开支就要转嫁到非常注重价格的顾客身上，因此他们会选择便宜的非认证的木材。因此，美国木材公司将更加趋向于保持他们的价格低廉，而不是获取证书。)
分析：这两段主体段除了主题句(主题句实际上也是用了因果逻辑法来完成的)以外，supporting details只用了因果论证方法，推一推原因，再推一推结果，很快就能把一段很好地论证出来，简洁、调理清晰、逻辑紧凑。
总结：独立作文中也可以通过想想主题句的原因和结果来论证主题句。
以上就是小编为大家带来的