我们在做托福阅读的时候经常会发现长难句只能根据单词的表面意思推个大概意思，当被问到具体的句子结构时就只能摇头晃脑。
怎么会这样呢？明明普通的句子找主干我都会，明明从句和非谓语动词等我也都学过，明明五大基本句型我也能倒背如流。
难的句子之所以难，主要常见的是以下五种干扰因素的互相结合；我们先看下常见的都有哪五种。
01.
后置定语
（常见的后置定语是介词短语/形容词短语/不定式/分词）
举例
Among the superbly preserved Messel fossils are insects with iridescent exoskeletons (hard outer coverings), frogs with skin and blood vessels intact, and even entire small mammals with preserved fur and soft tissue.
假设我们把这个介词形式的后置定语拿掉，句子是非常简单的（单纯的倒装对我们来说毫无难度）
Among the superbly preserved Messel fossils are insects with iridescent exoskeletons (hard outer coverings), frogs with skin and blood vessels intact, and even entire small mammals with preserved fur and soft tissue.
Among the superbly preserved Messel fossils are insects , frogs , and even entire small mammals.(被保存的很好的化石有昆虫，青蛙和小的哺乳动物)
（翻译：保存最完好的Messel化石包括有五彩斑斓的外骨骼(坚硬的外壳)的昆虫，皮肤和血管完整的青蛙，和皮毛和软组织都被保存下来的小型哺乳动物。）
02.同位语
大家都知道同位语用来解释名词，文章当中出现同位语是非常常见的，有些句子很贴心会出现that is , 或者 破折号，括号来辅助解释说明，有些就毫无特征。如果没有及时辨认出来，读得就会云里雾里。
举例
The ice extended westward from the Alaskan/Canadian mountains to the very edge of the continental shelf, the flat, submerged part of the continent that extends into the ocean.
the flat, submerged part of the continent that extends into the ocean 解释了前面的 continental shelf 大陆架的定义
（翻译：冰从阿拉斯加/加拿大山脉向西延伸，一直延伸到大陆架的边缘，那是一块平坦的、被水淹没的大陆，一直延伸到海洋。）
03.词组拆分结构
（compare...with/ associate..with / attribute...to 归因于 / between..and/ from..to , etc）
举例1
British archaeologist Colin Renfrew attributed the dramatic flowering of the Minoan civilization on Crete and through the Aegean to intensified trading contacts and to the impact of olive and vine cultivation on local communities
整句话的主干提取出来就很简单了。Colin Renfrew attributed sth, to A and to B
Colin Renfrew 把Minoan 文明归因于日渐紧密的贸易联系，以及葡萄与橄榄种植对当地的影响。
（翻译：英国考古学家Colin Renfrew认为克里特岛和爱琴海的米诺斯文明之所以能蓬勃发展，是由于贸易往来的加强，以及橄榄和葡萄种植对当地社区的影响）
举例2
This would have created a barrier of ice extending from the Alaska Peninsula, through the Gulf of Alaska and southward along the Northwest Coast of north America to what is today the state of Washington.
这会创造出一个从a地至b 地的冰障。
(翻译：这将形成一个冰的屏障，从阿拉斯加半岛，穿过阿拉斯加湾，向南沿北美西北海岸延伸到今天的华盛顿州。)
04.插入结构
（插入语经常会用逗号把句子主干或修饰内容前后隔开，造成阅读的干扰。插入语的内容是定语/同位语/状语这三种修饰成分）
举例
In order for the structure to achieve the size and strength necessary to meet its purpose, architecture employs methods of support that , because they are based on physical laws, have changed little since people first discovered them-even while building materials have changed dramatically.
注：分析句子时遇到插入语不代表可以直接跳过不看；建议把插入语后面的内容与前面先衔接上，再回过头看插入语。
..., architecture employs methods of support that have changed little since people first discovered them...
（翻译：为了使结构达到所需的大小和强度以满足其目的，建筑采用了自人们发现以来就没怎么变动过的支撑方法，因为它们基于物理定律——即使建筑材料发生了巨大的变化。）
05.并列结构
举例
Even though early exhibitors shaped their film programs by mixing films and other entertainments together in whichever way they thought would be most attractive to audiences or by accompanying them with lectures, their creative control remained limited.
注：看到并列的逻辑词 and/or , 需要把并列的对象理清楚。
即使早期电影放映者通过方式A 和方式B给电影塑形，他们对电影的创造性的控制还是很有限的。
（翻译：尽管早期的放映者通过将电影和其他娱乐节目以他们认为最能吸引观众的方式混合在一起，或者通过讲座与电影相结合 这两种方式来塑造他们的电影节目，但他们对电影的创造性的控制还是很有限的。）
以上就是常见的五种干扰因素，只要我们对这五种了然于心，我们理解句子就会更容易。更多关于托福考试的个性化问题欢迎咨询新航道官网
