新托福阅读考试主要考查考生对自然科学及社会科学领域学术研究性文章的阅读能力和理解能力。其句子成分复杂、逻辑错综，故掌握句子的起承转合关系，从而托福阅读考试中做到游刃有余，事半功倍。

    简言之，句际关系乃句子内部及句子之间的逻辑和意义关系。托福考试中常见句际关系有五种即：
 并列关系
 转折关系
 因果关系
 类比对比关系
 解释说明

下以托福阅读“十大题型”具体题目为例，解析五种句际关系的具体体现和应用：

并列关系

是语言应用中最常见的逻辑关系，其逻辑关系标志性连词、介词、副词或者词组，相信大家也能脱口而出：and, not only…but also,as well as,also, too,furthermore, moreover, in addition (to) additionally, alternatively等。
如： The rain seeps underground and the water may reappear later as springs.
The word seeps in the passage is closest in meaning to
○Dries gradually    ○Flows slowly    ○Freezes quickly    ○Warms slightly
答案为Flow slowly，因为dries, Freezes or Warms无法达成and之后的顺承动作reappear. 在此，通过对并列的逻辑关系和意义分析，答案显而易见。

又如下列修辞目的题：
In the paragraph, why does the author provide the information that 40 percent of American cattle are fattened in the High Plains?
○To suggest that crop cultivation is not the most important part of the economy of the High Plains.
○To indicate that not all economic activity in the High Plains is dependent on irrigation.
○To provide another example of how water from the Ogallala has transformed the economy of the High Plains.
○To contrast cattle-fattening practices in the High Plains with those used in other region of the United States.
The first wells were drilled into the Ogallala during the drought years of the early 1930’s. The ensuing rapid expansion of irrigation agriculture, especially from the 1950’s onward, transformed the economy of the region. More than 100,000 wells now tap the Ogallala. Modern irrigation devices, each capable of spraying 4.5 million liters of water a day, have produced a landscape dominated by geometric patterns of circular green islands of crops. Ogallala water has enabled the High Plains region to supply significant amounts of the cotton, sorghum, wheat, and corn grown in the United States. In addition, 40 percent of American grain-fed beef cattle are fattened here.

显然，问题句与上句为并列关系(in addition 标志词)，故此句的修辞目的是illustrate此段的main idea, 而段落给出了主题句：The ensuing rapid expansion of irrigation agriculture, especially from the 1950’s onward, transformed the economy of the region，故答案为选项3。

但值得注意的是，并列关系多以隐形的方式出现在托福阅读考题中，所谓隐形即句际间无标识词，以句子插入题和修辞目的题尤多，以下以句子插入题为例，如：
Some villages specialized in growing cabbages and carrots; others grew onions, mustard, and coriander; and still others produced fruit and cultivated trees in nurseries.
In addition to dairy farming and cultivating industrial crops, a third sector of the Dutch economy reflected the way in which agriculture was being modernized--horticulture. █In the sixteenth century, fruit and vegetables were to be found only in gardens belonging to wealthy people. █This changed in the early part of the seventeenth century when horticulture became accepted as an agricultural sector. █Whole villages began to cultivate fruit and vegetables. █The produce was then transported by water to markets in the cities, where the consumption of fruit and vegetables was no longer restricted to the wealthy.
首先阅读分析插入句，此句中无指代词，亦无逻辑标志词，但通读█前的语句，一█前句出现third sector：horticulture；二█前句fruit and vegetables：belonging to wealthy people；三█前句horticulture became accepted as an agricultural sector； 四█前句Whole villages：cultivate fruit and vegetables；显然插入句与四█前句存在隐形的承接关系。故答案为四█处。

转折关系

亦是非常普遍的语言逻辑关系，阐释两种相左或相反的状况、概念或意义。其标志词有:but, while, whereas, (al)though, even though(if),however, nonetheless, nevertheless等, 正如大家在日常英语学习中所见到那样，转折关系在托福阅读中的分布甚广，在词汇题、事实细节题、修辞目的题、句子插入题、句子简化题都曾高频出现。下以词汇题为例：
Although southem Maya areas received more rainfall than northern areas, problems of water were paradoxically more severe in the wet south.
The word "paradoxically” in the passage is closest in meaning to 2
○ usually     ○ surprisingly    ○ understandably    ○ predictably
语句中提到southern rainfall> north，而水问题south 更严重，显然有悖常理，故答案为surprisingly  

又如下列事实细节题：
According to the paragraph, what role did early exhibitors play in the presentation of movies in theaters?
○They decided how to combine various components with the film program.
○They advised film-makers on appropriate movie content.
○They often took part in the live-action performances.
○They produced and prerecorded the material that was shown in the theaters.
Although early exhibitors regularly accompanied movies with live acts, the substance of the movies themselves is mass-produced, prerecorded material that can easily be reproduced by theaters with little or no active participation by the exhibitor. 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. What audiences came to see was the technological marvel of the movies; the lifelike reproduction of the commonplace motion of trains, of waves striking the shore, and of people walking in the street; and the magic made possible by trick photography and the manipulation of the camera.

    据学员的答题情况看，此题准确率较低，如上所示此题的答案出处有两处，如果大家正确分析出转折逻辑所表达的含义，无论黑色或黄色的阴影句子都能给出我们Early exhibitors decided how to combine various components with the film program.的答案。

    佛家主张因果轮回，哲学强调因果联系的普遍性，托福阅读考试中的因果逻辑也处处可见；表示原因的常见词语有：because(of), since, for,  due to, owing to, as a result of (由于), result from(由…产生/造成), if (条件), unless；表结果的关系词：so, as a consequence, as a result, With the result that, consequently,  therefore, thus, accordingly, hence, thereby, result in（导致/造成）。如下列事实细节题：

According to the passage, which of the following is one of the reasons that tunas are in constant motion?
○They lack a swim bladder.
○They need to suck in more water than other fishes do.
○They have large muscles for breathing.
○They cannot open their mouths unless they are in motion.
Because they are always swimming, tunas simply have to open their mouths and water is forced in and over their gills. Accordingly, they have lost most of the muscles that other fishes use to suck in water and push it past the gills. In fact, tunas must swim to breathe. They must also keep swimming to keep from sinking, since most have largely or completely lost the swim bladder, the gas-filled sac that helps most other fish remain buoyant.
当我们读完since 引导的原因状语从句后,答案也就不言而喻了。
值得大家注意的是，因果关系作为推理题的一种推理逻辑，具有一定的特殊性。如下所示：
Which of the following can be inferred from the passage about articles manufactured before 1815?
○They were primarily produced by women.
○They were generally produced in shops rather than in homes.
○They were produced with more concern for quality than for speed of production.
○They were produced mostly in large cities with extensive transportation networks.
Before 1815 manufacturing in the United States had been done in homes or shops by skilled artisans. As master craft workers, they imparted the knowledge of their trades to apprentices and journeymen. In addition, women often worked in their homes part-time, making finished articles from raw material supplied by merchant capitalists. After 1815 this older form of manufacturing began to give way to factories with machinery tended by unskilled or semiskilled laborers. Cheap transportation networks, the rise of cities, and the availability of capital and credit all stimulated the shift to factory production.
从黑字部分我不难推理出 They were produced with more concern for quality than for speed of production，因为“done by skilled artisan". 由此可见，在推理题中因果推理一般为 文本语句(cause)→答案(result).

对比类比关系

一般出现在不找大家待见的推理题及修辞目的题中。但如果大家掌握了对比类比逻辑关系的应用方法，大家会发现这两个题目还是相当给力的。正如其字面意思所示对比(contrast)即对两事物差异的比较，标志词：as a contrast, in/by contrast, on contrast to, on/to the contrary, conversely；同理类比即为对两事物相似之处的比较，标志词：like,  similar to, similarly, the same as (with), as…as, just as (like)。下分别为推理题及作者目的题示例：
Which of the following can be inferred from the paragraph about early sea otters?
○It is not difficult to imagine what they looked like
○There were great numbers of them.
○They lived in the sea only.
○They did not leave many fossil remains.
It should be obvious that cetaceans-whales, porpoises, and dolphins-are mammals. They breathe through lungs, not through gills, and give birth to live young. Their streamlined bodies, the absence of hind legs, and the presence of a fluke and blowhole cannot disguise their affinities with land-dwelling mammals. However, unlike the cases of sea otters and pinnipeds (seals, sea lions, and walruses, whose limbs are functional both on land and at sea), it is not easy to envision what the first whales looked like. Extinct but, already fully marine cetaceans are known from the fossil record. How was the gap between a walking mammal and a swimming whale bridged? Missing until recently were fossils clearly intermediate, or transitional, between land mammals and cetaceans.
unlike the cases of sea otters, it is not easy to envision what the first whales looked like 对比推理→it is easy to envision what sea otters were like.
         
In the paragraph, why does the author give details about the estimated numbers of birds killed each year?
○To argue that wind farms should not be built along ridge lines
○To point out that the deaths of migratory birds exceed the deaths of birds of prey
○To explain why some environmentalists oppose wind energy
○To suggest that wind turbines result in relatively few bird deaths
Recorded deaths of birds of prey and other birds in wind farms in the United States currently amount to no more than 300 per year. By contrast, in the United States an estimated 97 million birds are killed each year when they collide with buildings made of plate glass, 57 million are killed on highways each year; at least 3.8 million die annually from pollution and poisoning; and millions of birds are electrocuted each year by transmission and distribution lines carrying power produced by nuclear and coal power plants.
97 million，57 million，3.8 million，millions of与 300 contrast, 说明300 small,故作者目的无非是 suggest that wind turbines result in relatively few bird deaths。

解释说明关系

中的例证法(illustration)作为一种重要的论证方法，被应用到各种文体中。在托福的阅读中对此种写作方法也多有考察。如：
Which of the following can be inferred from the paragraph about redwood forests?
○They become less stable as they mature.
○They support many species when they reach climax.
○They are found in temperate zones.
○They have reduced diversity during mid-successional stages.
Even the kind of stability defined as simple lack of change is not always associated with maximum diversity. At least in temperate zones, maximum diversity is often found in mid-successional stages, not in the climax community. Once a redwood forest matures, for example, the kinds of species and the number of individuals growing on the forest floor are reduced. In general, diversity, by itself, does not ensure stability. Mathematical models of ecosystems likewise suggest that diversity does not guarantee ecosystem stability—just the opposite, in fact. A more complicated system is, in general, more likely than a simple system to break down. (A fifteen-speed racing bicycle is more likely to break down than a child’s tricycle.)
显然，我们看到for example,马上会意识到黑体句为上句例证句，所以上句情况同时满足下句，故They（redwood forests）are found in temperate zones为正确答案。

值得强调的是，除例证法外（如上所示其标志词为for example/instance），托福考试中常考的解释说明关系还有符号的作用，如：（），--- ，：等，且此种逻辑关系多出现在修辞目的题。

In the paragraph, why does the author provide the information that “(A fifteen-speed racing bicycle is more likely to break down than a child’s tricycle)”?
○To illustrate a general principle about the stability of systems by using an everyday example
○To demonstrate that an understanding of stability in ecosystems can be applied to help understand stability in other situations
○To make a comparison that supports the claim that, in general, stability increases with diversity
○To provide an example that contradicts mathematical models of ecosystems
Even the kind of stability defined as simple lack of change is not always associated with maximum diversity. At least in temperate zones, maximum diversity is often found in mid-successional stages, not in the climax community. Once a redwood forest matures, for example, the kinds of species and the number of individuals growing on the forest floor are reduced. In general, diversity, by itself, does not ensure stability. Mathematical models of ecosystems likewise suggest that diversity does not guarantee ecosystem stability—just the opposite, in fact. A more complicated system is, in general, more likely than a simple system to break down. (A fifteen-speed racing bicycle is more likely to break down than a child’s tricycle.)
( ) 内的表述是为了explain 前句的内容, 显然对此题可一锤定音: illustrate a general principle about the stability of systems by using an everyday example。

    相信当有意识的逻辑分析最终转化为无意识阅读，大家能够在托福阅读做到”一目十行“，游刃有余。

作者简介：刘家华：上海新航道新托福阅读主讲，上海大学英语硕士。以过硬的学术功底对新托福阅读文章庖丁解牛，讲解深入浅出，技巧与技能结合到位。

(本文选自新航道《托福频道》2012年上半年刊)