为了帮助考生们更好地备考托福阅读考试，出国留学网托福栏目为大家带来“怎么解答托福阅读插入句子题”，希望对大家有所帮助哦!
这种题长这样：
Paragraph 8: Much of the water in a sample of water-saturated sediment or rock will drain from it if the sample is put in a suitable dry place. █But some will remain, clinging to all solid surfaces. █It is held there by the force of surface tension without which water would drain instantly from any wet surface, leaving it totally dry. █The total volume of water in the saturated sample must therefore be thought of as consisting of water that can, and water that cannot, drain away. █
13. Look at the four squares [█] that indicate where the following sentence could be added to the passage.
What, then, determines what proportion of the water stays and what proportion drains away?
Where would the sentence best fit?
怎么做插入句子题?
题目给出的句子(后文直接称之为“插入句”)能被放入其中一个位置的原因，就是这个句子与正确位置的前后文存在着某种语义上的联系。在阅读原文之前，若能根据一些信息词找出这种联系，并且推测前后文的信息，则我们在找答案的时候就会更准确。
做插入句子题时的步骤应该是酱紫的：
1)仔细阅读插入句，准确理解句意
2)根据句内信息词，推断插入位置前或后可能出现的内容
3)寻找复合推测的位置
4)将句子放入，讲插入句及前后两句话连起来通读一遍，检验是否流畅逻辑严谨、语意流畅
3. 信息词是啥?如何根据这类词推测?
插入句子题中出现的信息词分两类：1. 代词;2. 逻辑词
1)指代词
这里的指代词指的是：1. 代词;2. 定冠词the+名词所组成词。
代词(Pronoun)是代替名词或一句话的一种词类。the+名词的结构，在文中有时会起指代前文的作用。大部分出现指代词的插入句子题非常简单。
当题目的句子中出现指代词，插入位置前面必然会提到其指代的内容。这个时候，若我们能根据代词的种类、指代词的词义和插入句的句意推断出指代的具体内容，那么只需要将插入句放入出现该内容的句子之后的位置，即可满足指代关系，得到答案
# 情况1
如果四个位置中，只有一个位置前面出现句中指代词的指代对象，则这个位置就是我们的正确答案。
例题如下：
At times, it is actually possible to watch the effects of natural selection in host-parasite relationships. For example, Australia during the 1940 s was overrun by hundreds of millions of European rabbits. █ The rabbits destroyed huge expanses of Australia and threatened the sheep and cattle industries. █ In 1950, myxoma virus, a parasite that affects rabbits, was deliberately introduced into Australia to control the rabbit population. █ Spread rapidly by mosquitoes, the virus devastated the rabbit population. █ The virus was less deadly to the offspring of surviving rabbits, however, and it caused less and less harm over the years. Apparently, genotypes (the genetic make-up of an organism) in the rabbit population were selected that were better able to resist the parasite. Meanwhile, the deadliest strains of the virus perished with their hosts as natural selection favored strains that could infect hosts but not kill them. Thus, natural selection stabilized this host-parasite relationship.
This massive population began a century earlier as a mere twelve pairs of imported rabbits that reproduced quickly and developed into a major problem.
句中出现代词“this massive population”，这巨大的群体数量来自于“twelve pairs of imported rabbits”，则插入位置前面必然提到巨大的兔群数量。
只有第一个位置前面的句子提到“hundreds of millions of European rabbits”，可以构成指代的对象。所以A就是妥妥的正确答案。
# 情况2(较少出现)
如果四个位置中有多个位置的前面存在着“可能成为”指代词的指代对象的信息，那么往往只有其中一个内容能够符合指代词的“特性”。
例题如下：
While some European countries, such as England and Germany, began to industrialize in the eighteenth century, the Netherlands and the Scandinavian countries of Denmark, Norway, and Sweden developed later. █ All four of these countries lagged considerably behind in the early nineteenth century. █ However, they industrialized rapidly in the second half of the century, especially in the last two or three decades. █ In view of their later start and their lack of coal—undoubtedly the main reason they were not among the early industrializers—it is important to understand the sources of their success. █
During this period, Sweden had the highest rate of growth of output per capita of any country in Europe, and Denmark was second.
句中出现代词“this period”，插入位置前面必然提到某一个时期。同时，我们还要注意，句子还提到，这个时期里Sweden和Denmark经济发展特别好。
原文前三个位置之前的句子都提到了时期，分别是18世纪、19世纪上半叶和19世纪下半叶。然而前两句话所说的时期中，Sweden和Denmark都是处在落后的位置。而第三句话however转折之后的信息提到，19世纪下半叶，尤其是最后二三十年，它们(指的是Netherlands、Denmark、Norway和Sweden)发展特别快。也就是说，19世纪下半叶才是插入句中this period指代的内容，前两个时期都不能复合指代内容的特性。所以C是正确答案。
# 情况3
有些插入句由于代词性质比较特殊，又或对于代词的描述信息较少，故无法直接准确的推测出代词所指的内容，只能得到一个大概的方向。此时需要结合原文句意，逐个位置确认和排除。
例题如下：
The harsh conditions in deserts are intolerable for most plants and animals. Despite these conditions, however, many varieties of plants and animals have adapted to deserts in a number of ways. Most plant tissues die if their water content falls too low: the nutrients that feed plants are transmitted by water; water is a raw material in the vital process of photosynthesis; and water regulates the temperature of a plant by its ability to absorb heat and because water vapor lost to the atmosphere through the leaves helps to lower plant temperatures. █Water controls the volume of plant matter produced. █The distribution of plants within different areas of desert is also controlled by water. █Some areas, because of their soil texture, topographical position, or distance from rivers or groundwater, have virtually no water available to plants, whereas others do.█
For this reason, the total amount of plant material in a desert is often 100 times less than the amount of plant material in an equivalent area of temperate forest.
句中出现“for this reason”，前文所提到的信息导致“相同面积下，desert中的the total amount of plant material比temperate forest中的the total amount of plant material低100倍”。此时并不能直接得出this reason所指信息具体内容，但可知，该reason为插入句的原因，正确位置必然能满足这个因果关系。
