托福阅读事实信息题解析（上）

　　OG=official guide 官方指南

　　OG定义如下

　　这类题型要求学生识别文中明确给出的事实信息，包括细节、定义以及作者陈述的其他信息

　　通常而言，相关信息会在一到两句话中出现

　　只要遵循基本的方法以及一定的句子理解能力，想要搞定事实信息题并不难

　　来来来，让我们愉快地聊聊这类题的解题技巧!

　　按照国际惯例，先上例题!

　　Paragraph 1: The transition from forest to treeless tundra on a mountain slope is often a dramatic one. Within a vertical distance of just a few tens of meters, trees disappear as a life-form and are replaced by low shrubs, herbs, and grasses. This rapid zone of transition is called the upper timberline or tree line. In many semiarid areas there is also a lower timberline where the forest passes into steppe or desert at its lower edge, usually because of a lack of moisture.

　　2. Where is the lower timberline mentioned in paragraph 1 likely to be found?

　　In an area that has little water

　　In an area that has little sunlight

　　Above a transition area

　　On a mountain that has on upper timberline.

　　就问你看懂提问内容了吗?

　　第一段中所提及的lower timberline有可能在哪里被发现?

　　带着这个问题我们回到原文段落，带着关键词lower timberline逐句阅读，前三句均为提及lower timberline。直到In many semiarid..这句话，说到在很多半干旱地区，有lower timberline，所以答案判断为半干旱地区。

　　然后看选项，A的意思是几乎没有水的地方，就对应原文的信息，所以A是正确的。

　　处理事实信息题基本的做题步骤

　　1.读题，理解题目的提问内容并提炼关键词

　　2.带着关键词阅读原文段落，寻找对应信息

　　3.核对选项

　　所以想要做对一道细节题，第一步永远是准确理解题目。在实际的考试中，大部分的细节题题目都是比较容易理解的。

　　但是!偶尔会出现较难理解的题目，这就非常考验考生的单句分析能力。

　　上例题，就问你服不服!

　　Geographic isolation can also proceed slowly, over great spans of time. We find evidence of such extended events in the fossil record, which affords glimpse into the breakup of formerly continuous environments. For example, during past ice ages, glaciers advanced down through North America and Europe and gradually cut off parts of populations from one another. When the glaciers retreated, the separated populations of plants and animals came into contact again. Some groups that had descended from the same parent population were no longer reproductively compatible – they had evolved into separate species. In other groups, however, genetic divergences had not proceeded so far, and the descendants could still interbreed – for them, reproductive isolation was not completed, and so speciation had not occurred.

　　6. According to paragraph 3, separation of subpopulations by glaciers resulted in speciation in those groups of plants and animals that

　　Were reproductively isolated even after the glaciers disappeared

　　Had adjusted to the old conditions caused by the glaciers

　　Were able to survive being separated from their parent population

　　Had experienced some genetic divergences from their parent population

　　救命!太难了~~

　　来来来，解析在此!

　　这道题的题目比较难理解，因为题干中欠缺了定语从句的内容，所以很多同学在理解的时候搞不懂题目到底问什么东西。

　　其实我们把定语从句带回题目就可以得出这样的理解：“冰川所造成的亚种隔离导致了什么样的动植物群体的新物种形成?”这就是题目真正所提问的内容。

　　然后再根据关键词定位到原文中for example的句子，可以得出以下理解：“冰川会造成群体隔离，而当冰川撤退后，被分离的物种又一次开始互相接触。有一些物种在重新接触后，已经无法繁殖兼容，意味着他们已经形成了新物种。而另一些被分离的物种，基因差别并没有那么大，他们仍旧可以互相繁殖，对他们而言，新物种并没有形成”再结合题目的提问内容，可以得出，那么在重新接触后，已经无法互相繁殖的群体形成了新物种，所以答案选A。

　　那么读懂了题干的提问内容是不是一定能做对题目呢?答案是否定的。有时候，题目的提问内容并不是那么容易在原文中找到对应，因为原文的表达很有可能发生了同义转换，考生需要识别出。

　　虽然你可能有点晕了，但还是要上例题!

　　坚持一下，最后一题啦!

　　Paragraph 5: Spartina was transported to Washington State in packing materials for oysters transplanted from the east coast in 1894. Leaving its insect predators behind, the cordgrass has been spreading slowly and steadily along Washington’s tidal estuaries on the west coast, crowding out the native plants and drastically altering the landscape by trapping sediment. Spartina modifies tidal mudflats, turning them into high marshes inhospitable to the many fish and waterfowl that depend on the mudflats. It is already hampering the oyster harvest and the Dungeness crab fishery, and it interferes with the recreational use of beaches and waterfronts.

　　9.According to paragraph 5, Spartina negatively affects wildlife in estuaries by

　　trapping fish and waterfowl in sediment

　　preventing oysters from transplanting successfully

　　turning mudflats into high marshes and salt meadows

　　expanding the marshy fringes of salt meadows

　　听“大神”来解析题目——

　　题目问S如何负面地影响了野生生命。在原文中并没有出现类似表达，甚至没有wildlife这个单词，所以我们在阅读原文的时候，就要做好准备，去寻找题干信息的同意转换。

　　在这里，原文中提到Spartina modifies tidal mudflats, turning them into high marshes inhospitable to the many fish and waterfowl that depend on the mudflats.这句话中的many fish and waterfowl其实就是题目中的wildlife，而inhospitable就对应negatively。

　　所以这句话就包含了题目的提问内容，也就是我们答案句。答案选C。

　　那么如果读懂了题目，也找到了原文的对应信息，是不是就不会出错了呢?同样，这其中也包含玄机!

　　今天篇幅有限，在下次的讲解中，就和大家来探讨一下另一种情况：在找到题目的提问内容，也就是大家所谓的对应句后，很有可能答案并不在那句话中，而在前后句里。