托福阅读因果逻辑解析 备考生这些题型get起来

都说托福阅读中逻辑关系非常重要，那么我们今天来简单聊聊因果逻辑。首先问大家一个问题：你认识的因果逻辑词有哪些?(能列出 10 个吗?不能的话看完本文记得拿小本本记下吧)

一、因果逻辑之句子简化题

一提到因果逻辑，可能大部分考生顿时想到的是句子简化题。因为有相当比例的句子简化题中是有逻辑关系的句子，的确可以先从原句逻辑关系出发，先排除明显逻辑错误的选项，剩下的再进行核对筛选。但我们在运用任何逻辑关系解题的时候可千万别忘了句子主干哦。下面我们看几个例题：

例题 1

The frequency with which certain simple motifs appear in these oldest sites has led rock-art researchers to adopt a deive term—the Panaramitee style—a label which takes its name from the extensive rock pavements at Panaramitee North in desert South Australia, which are covered with motifs pecked into the surface.

(A)The oldest rock art sites have simpler motifs than the best known sites of Panaramitee North.

(B)Because motifs primarily associated with the Panaramitee region are common in the oldest sites the term Panaramitee style has become the general term for rock art of this type.

(C)Because the Panaramitee style is so common in the older sites, researchers have described it most extensively.

(D)The motifs carved in the rocky surface of the Panaramitee region make up the oldest form of rock art discovered in Australia.

天啊，这个句子那么长!但提取主干后，句子将变得非常简单：

The frequency had lead rock-art researchers to adopt a deive term—the Panramitee style.

我们发现这个句子的谓语动词是 lead to，是个隐性的因果逻辑词。也就是说，本句话较想表达的意思是，某个东西的频繁出现，是研究者们采用 P style 这个术语的原因。

这时我们来看四个选项，A 选项强调的是对比关系，一看就可以排除的炮灰选项。

D 选项的主干是 The motifs make up the oldest form. 跟原句的主干完全不符合，又可排除。

大部分同学都是纠结 B 和 C，而且还不少同学认为这两个选项读完根本就是一个意思, excuse me?!那么接下来我们就得分析下选项中的原因和结果与原句的原因和结构能否对应的上，会不会因果倒置。B 和 C 选项一个较大的区别，就在于 B 选项中 P style 是句子的结果，而 C 选项中 P style 出现在了原因部分。原句的 P style 是句子的结果，所以，正确答案就很明了了，选 B!

咱们再来看另一个例题：

例题 2

However, no group or species can maintain its dominance indefinitely, and when, after over 200 million years, the age of dinosaurs came to a dramatic end about 65 million years ago, mammals began to flourish, evolving from relatively few types of small terrestrial animals into the myriad of diverse species, including bats and whales, that we know today.

(A)The dominance of dinosaurs came to an end 65 million years ago, at which time mammals began to flourish and diversify.

(B)Because no group of species can remain dominant forever, mammals became the dominant group when dinosaurs became extinct.

(C)After being the dominant group for more than 200 million years, the age of dinosaurs came to a dramatic end 65 million years ago.

(D)The diverse group of mammals that we know today, including bats and whales, evolved from small terrestrial forms that had been dominated by dinosaurs.

句首的 However 虽然是个转折逻辑词，但对于这道题而言是没有用的，因为这明显是跟上一句话进行转折，而句子简化题考查的是句内逻辑，而不是句间逻辑。这句话是由 and 连接起来的两个句子，所以不少同学觉得这两句话就是并列关系。

这两个句子的主干信息为 no group or species can maintain its dominance 和 mammals began to flourish. 那么较完美的正确选项应该是肯定要包含这两个主干信息的。

大部分同学是在 A 和 B 之间纠结，觉得 A 呢没毛病，B 也挺对的，但是多了个 because 不太敢选。A 相对于 B 而言，是属于信息残缺的选项，B 选项的信息和原句的信息匹配度更高。

但是 because 如何解释呢?举个简单的例子：

It’s raining outside and I decide to order take-out food.

我们可否理解成因为外面下雨了，所以我决定订外卖?这也是说得通的。所以在个别情况下，两个并列的句子也可以有隐含的因果逻辑关系，看句意而定。这题便是，两个句子的核心内容可理解成，因为没有任何物种可以一直维持统治地位，所以，后来哺乳动物 flourish 了。再通过阅读细节可发现 mammals began to flourish 正是恐龙灭绝之后。所以这时我们再对比一下 A 和 B，B 选项和原句的还原度是比 A 好的。

二、因果逻辑之细节题

因果逻辑其实无处不在，另一个经常考察此逻辑关系的题型是细节题。现在我们来看几个稍微有点没那么明显的因果逻辑的考题。

例题 3

The time had come to formulate a hypothesis. The investigators theorized that about 20 million years ago, the Mediterranean was a broad seaway linked to the Atlantic by two narrow straits. Crustal movements closed the straits, and the landlocked Mediterranean began to evaporate. Increasing salinity caused by the evaporation resulted in the extermination of scores of invertebrate species…Soon layer of oceanic ooze began to accumulate above the old hard layer.

Which of the following was responsible for the evaporation of the Mediterranean's waters?

(A)the movements of earth's crust

(B)the accumulation of sediment layers

(C)changes in the water level of the Atlantic Ocean

(D)changes in earth's temperature

本题题干中看到 responsible for，马上反应到考查的是因果逻辑。不少同学可以定位到本段第三句话，但句子中并没有找到明显的因果逻辑词于是不敢判断答案，于是继续往下读，怎么读都觉得没有正确答案同时又浪费了很多时间。

其实这题考的因果逻辑这个考点跟我们上一个句子简化题的例题是很相似的。两个句子并列用 and 连接，但是也有隐含的因果逻辑关系。因为地壳运动封闭了海峡，被陆地包围的地中海也开始蒸发。如果能识别到这层关系，则应该可以秒选 A 了。

例题 4

Medieval Europe gave new importance to reliable time. The Catholic Church had its seven daily prayers, one of which was at night, requiring an alarm arrangement to waken monks before dawn. And then the new cities and towns, squeezed by their walls, had to know and order time in order to organize collective activity and ration space.

Why did the medieval church need an alarm arrangement ?

(A)The alarm warned the monks of discord or strife in the town.

(B)The church was responsible for regulating working hours and market hours.

(C)The alarm was needed in case fires were not put out each night.

(D)One of the church’s daily rituals occurred during the night.

这是个细节题，通过题干可定位到本段第二句话。题目问的是 why，但在原文中不能直接找到 because 或 contribute to 等其他因果逻辑词。但我们在定位准确的前提下，仔细在读读第二句话，发现这个句子有现在分词做状语的成分，而 v-ing 是可以做结果状语的。那么 requiring an alarm arrangement 的前面信息的同义改写便是这道题的正确答案。此题正确答案为 D。

本文仅简单列举了因果逻辑关系在阅读中的几种考法，它还可以出现在推断题，句子插入题中，由于篇幅有限就不一一列举例题了。识别因果逻辑的不同表现形式是可以帮助提高我们的答题效率的一个突破点。回到本文提出的第一个问题，笔者罗列了一些给大家参考一下：

1、显性因果逻辑词：

since, because, because of, thus, hence, as a result, result from, responsible for, due to, so that, consequently, account for, explain, factor, outcome……

2、隐性因果逻辑词：

lead to, stimulate, enable, motivate, encourage, contribute to, trigger, give rise to, induce, affect, damage, impact, depend on, rely on......