托福考试阅读技巧一、逆向推断
这类推断比较明显，往往在关键句当中有能利用的时间，地点，还有具体的取非词，找到之后针对该句的意思取个反就行。
1.The nineteenth century brought with it a burst of a new discoveries and inventions that revolutionized the candle industry and make lighting available to all. In the early-to-mid –nineteenth century, a process was developed to refine tallow with alkali and sulfuric acid. The result was a product called stearin.This breakthrough meant that it was possible to make allow candles that would not produce the usual smoke and rancid odor.
Which of the following can be inferred from this paragraph about candles before the nineteenth century?
A They did not smoke when they were burned
B They produced a pleasant odor as they burned
C They were not available to all
D They contained sulfuric acid.
这句话根据candles定位到第一句话，发现里面有the nineteenth century这个时间点，那题干问的是before the nineteenth century的情况，所以果断取个反选C
2.This was before the steam locomotive, and canal building was at its height. The companies building the canals to transport coal needed surveyors to help them find the coal deposits worth mining as well as to determine the best courses for the canals. This job gave Smith an opportunity to study the fresh rock outcrops created by the newly dug canal. He later worked on similar jobs across the length and breadth of England, all the while studying the newly revealed strata and collecting all the fossils he could find. Smith used mail coaches to travel as much as 10,000 miles per year. In 1815 he published the first modern geological map, “A Map of the Strata of England and Wales with a Part of Scotland,” a map so meticulously researched that it can still be used today.
Which of the following can be inferred about canal building?(2)
○ Canals were built primarily in the south of England rather than in other regions.
○ Canal building decreased after the steam locomotive was invented.
○ Canal building made it difficult to study rock strata which often became damaged in the process.
○ Canal builders hired surveyors like Smith to examine exposed rock strata.
这道题同样根据canal building定位到第一句，在steam locomotive出现之前，cananl building一直是稳坐泰山的地位，而题干问现在canal building怎样，所以取个反，选B。
托福考试阅读技巧二、正向推断
这类推断适应于题干与原文关系属于抽象与具体关系(整体与部分关系)，往往我们解题时要找出相应句子之间的关系。
1.Another major discovery was made in Egypt in 1989. Several skeletons of another early whale, Basilosaurus, were found in sediments left by the Tethys Sea and now exposed in the Sahara desert. This whale lived around 40 million years ago, 12 million years after Pakicetus. Many incomplete skeletons were found but they included, for the first time in an archaeocyte, a complete hind leg that features a foot with three tiny toes. Such legs would have been far too small to have supported the 50-foot-long Basilosaurus on land. Basilosaurus was undoubtedly a fully marine whale with possibly nonfunctional, or vestigial, hind legs.
It can be inferred that Basilosaurus bred and gave birth in which of the following locations (4)
○On land
○Both on land and at sea
○In shallow water
○In a marine environment
本题问Basilosaurus在哪里哺育生命，我们发现原文里没有直接体现相关概念的定位句，但是标红句告诉我们Basilosaurus是一个海洋生物，那试想一下，海洋生物在哪里哺育生命?当然在海里了，所以选D。
2.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.
Which of the following can be inferred about redwood forests?(3)
○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.
这道题也很经典，首先根据题干定位词redwood forest定位到标红句，但是仔细看一下4个选项中没有能直接体现相关意思的(比如A选项，They指代的是redwood forest，而原文指的是species的数量减少)，这时候往前找更抽象的句子，发现前一句，说at least in temperate zones那这就表明下面的概念都是在temperate zones这个大环境下描述的，那么作为细节出现的redwood forest当然也应该满足这个条件。所以选C。
