发布时间：2017-05-11 来源：新东方在线 发布人：young
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?
插入句子题中出现的信息词分两类：1. 代词;2. 逻辑词
这里的指代词指的是：1. 代词;2. 定冠词the 名词所组成词。
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。
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.
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。
找到1、2位置之间的句子“Water controls the volume of plant matter produced.”。其中the volume of plant matter和the total amount of plant material意思相同，其次由于water的控制作用，确实会导致两个水量不同的地区(desert和forest)产生差别，前后逻辑非常严谨，所以B是正确答案。
Less colorful birds and animals that inhabit the rain forest tend to rely on forms of signaling other than the visual, particularly over long distances. █ The piercing cries of the rhinoceros hornbill characterize the Southeast Asian rain forest, as do the unmistakable calls of the gibbons. █ In densely wooded environments, sound is the best means of communication over distance because in comparison with light, it travels with little impediment from trees and other vegetation. █ In forests, visual signals can be seen only at short distances, where they are not obstructed by trees. █ The male riflebird exploits both of these modes of signaling simultaneously in his courtship display. The sounds made as each wing is opened carry extremely well over distance and advertise his presence widely. The ritualized visual display communicates in close quarters when a female has approached.
There is also the long, rather terrifying call of the male orangutan, which carries over considerable distances to advertise his presence.
Paragraph 1: Of all the physiological differences in human sleep compared with wakefulness that have been discovered in the last decade, changes in respiratory control are most dramatic. Not only are there differences in the level of the functioning of respiratory systems, there are even changes in how they function. Movements of the rib cage for breathing are reduced during sleep, making the contractions of the diaphragm more important. █ Yet because of the physics of lying down, the stomach applies weight against the diaphragm and makes it more difficult for the diaphragm to do its job. █ However, there are many other changes that affect respiration when asleep.
Paragraph 2: █ During wakefulness, breathing is controlled by two interacting systems. █The first is an automatic, metabolic system whose control is centered in the brain stem. It subconsciously adjusts breathing rate and depth in order to regulate the levels of carbon dioxide (CO2) and oxygen (O2), and the acid-base ratio in the blood. The second system is the voluntary, behavioral system. Its control center is based in the forebrain, and it regulates breathing for use in speech, singing, sighing, and so on. It is capable of ignoring or overriding the automatic, metabolic system and produces an irregular pattern of breathing.
To better understand breathing during sleep, it is, however, helpful to first understand how respiration works in general.
Paragraph 3: It used to be believed that before 3000 B.C.E. the political and economic life of the cities was centered on their temples, but it now seems probable that the cities had secular rulers from earliest times. █Within the city lived administrators, craftspeople, and merchants. (Trading was important, as so many raw materials, the semiprecious stones for the decoration of the temples, timbers for roofs, and all metals, had to be imported.) █An increasingly sophisticated system of administration led in about 3300 B.C.E. to the appearance of writing. █The earliest script was based on logograms, with a symbol being used to express a whole word. █The logograms were incised on damp clay tablets with a stylus with a wedge shape at its end. (The Romans called the shape cuneus and this gives the script its name of cuneiform.) Two thousand logograms have been recorded from these early centuries of writing. A more economical approach was to use a sign to express not a whole word but a single syllable. (To take an example: the Sumerian word for " head” was “sag.” Whenever a word including a syllable in which the sound “sag” was to be written, the sign for “sag" could be used to express that syllable with the remaining syllables of the word expressed by other signs.) By 2300 B.C.E. the number of signs required had been reduced to 600, and the range of words that could be expressed had widened. Texts dealing with economic matters predominated, as they always had done; but at this point works of theology, literature, history, and law also appeared.
City life was diverse, and the population was engaged in a variety of occupations.
插入句并没有指代词和逻辑词出现，只表达了句意“城市里有着多种多样的生活和工作”。这个时候，我们直接回原文，寻找哪个句子提到或围绕“城市里的生活和工作”进行论述。发现原文第二句话“Within the city lived administrators, craftspeople, and merchants.”，其实就是具体的阐述city里的工作都有什么，人们都干嘛，与插入句句意是重复的。且前面一句话最后提到了secular，暗指的其实就是日常生活和工作。所以A是最合适的位置。
Another flaw of the tiredness theory is that yawning does not raise alertness or physiological activity, as the theory would predict. When researchers measured the heart rate, muscle tension and skin conductance of people before, during and after yawning, they did detect some changes in skin conductance following yawning, indicating a slight increase in physiological activity. However, similar changes occurred when the subjects were asked simply to open their mouths or to breathe deeply. Yawning did nothing special to their state of physiological activity. Experiments have also cast serious doubt on the belief that yawning is triggered by a drop in blood oxygen or a rise in blood carbon dioxide. █Volunteers were told to think about yawning while they breathed either normal air, pure oxygen, or an air mixture with an above-normal level of carbon dioxide. █If the theory was correct, breathing air with extra carbon dioxide should have triggered yawning, while breathing pure oxygen should have suppressed yawning. █In fact, neither condition made any difference to the frequency of yawning, which remained constant at about 24 yawns per hour. █Another experiment demonstrated that physical exercise, which was sufficiently vigorous to double the rate of breathing, had no effect on the frequency of yawning Again the implication is that yawning has little or nothing to do with oxygen.
This, however, was not the case
本句既出现代词“this”也出现逻辑词“however”，不过this指代内容比较模糊。可以推测出，前面提到的句意，在插入句中得到了否定(not the case)。其次，根据however存在的转折和承上启下的关系，后文非常有可能展开论述this指代内容为何不是真实情况(not the case)。结合推测，找到C位置的前后，符合这个关系。前一句话说“如果理论正确，则呼吸二氧化碳多会导致打哈欠增多，呼吸氧气多会减少打哈欠”，后一句话表示“真实情况是(in fact)，不管是二氧化碳还是氧气，打哈欠的频率都是相同的”，所以后一句话就是通过描述真实情况，而对前一句理论所推测和估计的情况起到反驳的作用。
Paragraph 1: It has long been accepted that the Americas were colonized by a migration of peoples from Asia, slowly traveling across a land bridge called Beringia (now the Bering Strait between northeastern Asia and Alaska) during the last Ice Age. █The first water craft theory about the migration was that around 11,000-12,000 years ago there was an ice-free corridor stretching from eastern Beringia to the areas of North America south of the great northern glaciers. It was the midcontinental corridor between two massive ice sheets-the Laurentide to the west-that enabled the southward migration. █But belief in this ice-free corridor began to crumble when paleoecologist Glen MacDonald demonstrated that some of the most important radiocarbon dates used to support the existence of an ice-free corridor were incorrect. █He persuasively argued that such an ice-free corridor did not exist until much later, when the continental ice began its final retreat. █
Moreover, other evidence suggests that even if an ice-free corridor did exist, it would have lacked the resources needed for human colonization.
本句出现“moreover”，表示插入句和前文是递进关系，表示进一步的论述。后面出现“other evidence”，指出前面应该有某些evidence。句中出现even if的让步关系，再结合句意“此外，其他证据表明，即使无冰走廊确实存在，它也会缺乏人类居住所必须的资源”，可以推测出，前文的evidence应该是在论证“ice-free corridor”不存在，这里才会递进 让步，表示“即使存在，也…”的句意。根据这个推测发现C位置前面一句话指出：Glen Macdonald证明支持“ice-free corridor”存在的信息其实是错误的。也就是在暗示“ice-free corridor”不存在，能够和插入句紧密连接。