托福考试是申请美国留学的考生都要参加的考试。以下是考生分享的2012年10月27日托福阅读考试机经回忆的内容，即将参加托福考试的考生们可以借鉴参考一下试题，为下一次的新托福考试做好充足准备。希望对大家的美国留学托福阅读考试有所帮助。

第一篇

考生回忆

动物学家和一个比较分析(Comparative Analyst)关于动物行为的看法;

前者认为动物行为由先天决定;

后者认为后天习成

解析：本篇文章属于动物学文章，根据考生回忆本篇文章应该属于典型的对比比较类文章。比较的对象为两者对动物行为的不同看法。考生阅读此类文章的重点在于一定要将分类的标准以及对比分类标准当中对应的特点提取准确。本类型文章最后一题可能考察表格题。

TOPIC 动物行为学

Ethology

A. Instinct

The Merriam-Webster dictionary defines instinct as a largely inheritable and unalterable tendency of an organism to make a complex and specific response to environmental stimuli without involving reason. For ethologists, instinct means a series of predictable behaviors for fixed action patterns. Such schemes are only acted when a precise stimulating signal is present. When such signals act as communication among members of the same species, they are known as releasers. A notable example of a releaser is the beak movements in many bird species performed by the newborns, which stimulates the mother's regurgitating process to feed her offspring. Another well-known case is the classic experiments by Tinbergen on the Graylag Goose. Like similar waterfowl, the goose rolls a displaced egg near its nest back to the others with its beak. The sight of the displaced egg triggers this mechanism. If the egg is taken away, the animal continues with the behavior, pulling its head back as if an imaginary egg is still being maneuvered by the underside of its beak. However, it also attempts to move other egg-shaped objects, such as a giant plaster egg, door knob, or even a volleyball back into the nest. Such objects, when they exaggerate the releasers found in natural objects, can elicit a stronger version of the behavior than the natural object, so that the goose ignores its own displaced egg in favor of the giant dummy egg. These exaggerated releasers for instincts were named supernormal stimuli by Tinbergen. Tinbergen found he could produce supernormal stimuli for most instincts in animals—such as cardboard butterflies that male butterflies preferred to mate with if they had darker stripes than a real female, or dummy fish that a territorial male stickleback fish fought more violently than a real invading male if the dummy had a brighter-colored underside. Harvard psychologist Deirdre Barrett has done research pointing out how easily humans also respond to supernormal stimuli for sexual, nurturing, feeding, and social instincts. However, a behavior only made of fixed action patterns would be particularly rigid and inefficient, reducing the probability of survival and reproduction, so the learning process has great importance, as does the ability to change the individual's responses based on its experience. It can be said that the more the brain is complex and the life of the individual long, the more its behavior is "intelligent.

B. Learning

Learning occurs in many ways, one of the most elementary being habituation. This process consists of ignoring persistent or useless stimuli. An example of learning by habituation is the one observed in squirrels: When one of them feels threatened, the others hear its signal and go to the nearest refuge. However, if the signal comes from an individual that has caused many false alarms, the other squirrels ignore the signal.

Another common way of learning is by association, where a stimulus is, based on the experience, linked to another one that may not have anything to do with the first one. The first studies of associative learning were made by Russian physiologist Ivan Pavlov. An example of associative behaviour is observed when a common goldfish goes close to the water surface whenever a human is going to feed it, or the excitement of a dog whenever it sees a collar as a prelude for a walk.

a. Imprinting

Example of imprinting in a moose

Being able to discriminate the members of one's own species is also of fundamental importance for reproductive success. Such discrimination can be based on a number of factors. However, this important type of learning only takes place in a very limited period of time. This kind of learning is called imprinting, and was a second important finding of Lorenz. Lorenz observed that the young of birds such as geese and chickens followed their mothers spontaneously from almost the first day after they were hatched, and he discovered that this response could be imitated by an arbitrary stimulus if the eggs were incubated artificially and the stimulus were presented during a critical period that continued for a few days after hatching.

b. Imitation

Imitation is often an important type of learning. A well-documented example of imitative learning occurred in a group of macaques on Hachijojima Island, Japan. The macaques lived in the inland forest until the 1960s, when a group of researchers started giving them potatoes on the beach: soon, they started venturing onto the beach, picking the potatoes from the sand, and cleaning and eating them. About one year later, an individual was observed bringing a potato to the sea, putting it into the water with one hand, and cleaning it with the other. Her behaviour was soon imitated by the individuals living in contact with her; when they gave birth, they taught this practice to their young.

The National Institutes of Health reported that capuchin monkeys preferred the company of researchers who imitated them to that of researchers who did not. The monkeys not only spent more time with their imitators but also preferred to engage in a simple task with them even when provided with the option of performing the same task with a non-imitator.

第二篇

考生回忆

通过Ammonia和Methane来分析是否有生命迹象 Mars上两种物质Methane 和Ammonia，说这可能是生物新陈代谢产生，还有说是火山喷发产生，有人说那个火山现在已经死了，所以可能有物种存在。可是气温低啥的。还说 Methane和Ammonia都是相对新的，因为咱用仪器去探测，当它击Mar的表面时候，Methane和Ammonia就decompose成别的 了。

解析：此篇文章属于天文类文章。相关火星类文章TPO当中也曾经出现过RUNNING WATER ON MARS. 根据考生回忆，本篇文章的重点在于对于不同论据作者的态度以及论据对观点的支持程度。

TOPIC 火星上是否有生命

Atmosphere of Mars: Methane

Trace amounts of methane in the atmosphere of Mars were discovered in 2003 and verified in 2004. As methane is an unstable gas, its presence indicates that there must be an active source on the planet in order to keep such levels in the atmosphere. It is estimated that Mars must produce 270 ton/year of methane, but asteroid impacts account for only 0.8% of the total methane production. Although geologic sources of methane such as serpentinization are possible, the lack of current volcanism, hydrothermal activity or hotspots are not favorable for geologic methane. It has been suggested that the methane was produced by chemical reactions in meteorites, driven by the intense heat during entry through the atmosphere. However, research published in December 2009, ruled out this possibility.

The existence of life in the form of microorganisms such as methanogens is among possible but as yet unproven sources. If microscopic Martian life is producing the methane, it likely resides far below the surface, where it is still warm enough for liquid water to exist.

Since the 2003 discovery of methane in the atmosphere, some scientists have been designing models and in vitro experiments testing growth of methanogenic bacteria on simulated Martian soil, where all four methanogen strains tested produced substantial levels of methane, even in the presence of 1.0wt% perchlorate salt. The results reported indicate that the perchlorates discovered by the Phoenix Lander would not rule out the possible presence of methanogens on Mars.

A team led by Levin suggested that both phenomena—methane production and degradation—could be accounted for by an ecology of methane-producing and methane-consuming microorganisms.

BBC News: Ammonia on Mars could mean life

Researchers say its spectral signature has been tentatively detected by sensors on board the European Space Agency's orbiting Mars Express craft.

Ammonia survives for only a short time in the Martian atmosphere so if it really does exist it must be getting constantly replenished.

There are two possible sources: either active volcanoes, none of which have been found yet on Mars, or microbes.

Suite of molecules

"Ammonia could be the key to finding life on Mars," one US space agency (Nasa) scientist told BBC News Online.

Spectral evidence for the gas was seen by the Planetary Fourier Spectrometer (PFS) on Mars Express.

Professor Vittorio Formisano, principal investigator for the instrument, is expected to release details of new findings from the PFS at an international conference being held next week in Paris.

The PFS is sensitive to radiation in the spectral region of 1.2-5 microns and 5-50 microns - a region rich with important molecules such as water and carbon dioxide. Ammonia has a spectral line at 10 microns.

Although Mars Express has been in orbit around Mars since December 2003, scientists have so far only analysed a fraction of the data the PFS has produced.

Researchers say this is because they are still coming to terms with the complexities of the PFS as well as coping with some nagging power problems on Mars Express.

So far the PFS has observed a depletion of carbon dioxide and an enrichment of water vapour over some of the large extinct volcanoes on Mars. But it is the detection of minor compounds, possible in the sensors high-resolution mode, which are causing excitement.

The tentative detection of ammonia comes just a few months after methane was found in the Martian atmosphere. Methane is another gas with a possible biological origin.

Ammonia is not a stable molecule in the Martian atmosphere. If it was not replenished in some way, it would only last a few hours before it vanished.

One possibility the scientists have had to rule out is that the ammonia comes from the air bags of the failed Beagle 2 mission. Analysis has revealed that the suspected ammonia's distribution is not consistent with this explanation.

Life on Mars?

The importance of ammonia is that it is a compound of nitrogen and hydrogen.

Nitrogen is rare in the Martian environment but because no form of terrestrial life can exist without it, the presence of ammonia may indicate that Martian microbial life is hoarding it.

"There are no known ways for ammonia to be present in the Martian atmosphere that do not involve life," the Nasa scientist said. The twin US rovers that landed on the Red Planet in January will be unable to answer the question of the ammonia's origin as they are designed for geological work.

But future missions could include sensors to analyse the ammonia to determine if it has a biological or volcanic origin. Lava deposited on to the surface, or released underground, could produce the gas.

But, so far, no active volcanic hotspots have been detected on the planet by the many spacecraft currently in orbit.

第三篇

考生回忆：

是Pueblo人一起居住(living together)的形式是如何产生的，有环境变化的因素等等，然后有专家认为这种居住方式反映了Pueblo人社会经济的组织方式

解析：本篇文章描述主体与TPO但中文章moving to Pueblos的主题类似，而且根据考生回忆应该有部分内容的重合，故本篇文章可以参照TPO文章moving to pueblos.

Moving into Pueblos

In the Mesa Verde area of the ancient North American Southwest, living patterns changed in the thirteenth century, with large numbers of people moving into large communal dwellings called pueblos, often constructed at the edges of canyons, especially on the sides of cliffs. Abandoning small extended-family households to move into these large pueblos with dozens if not hundreds of other people was probably traumatic. Few of the cultural traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. For people in cliff dwellings, hauling water, wood, and food to their homes was a major chore. The stress on local resources, especially in the firewood needed for daily cooking and warmth, was particularly intense, and conditions in aggregated pueblos were not very hygienic.

Given all the disadvantages of living in aggregated towns, why did people in the thirteenth century move into these closely packed quarters? For transitions of such suddenness, archaeologists consider either pull factors (benefits that drew families together) or push factors (some external threat or crisis that forced people to aggregate). In this case, push explanations dominate.

Population growth is considered a particularly influential push. After several generations of population growth, people packed the landscape in densities so high that communal pueblos may have been a necessary outcome. Around Sand Canyon, for example, populations grew from 5 -12 people per square kilometer in the tenth century to as many as 30 - 50 by the 1200s. As densities increased, domestic architecture became larger, culminating in crowded pueblos. Some scholars expand on this idea by emphasizing a corresponding need for arable land to feed growing numbers of people: construction of small dams, reservoirs, terraces, and field houses indicates that farmers were intensifying their efforts during the 1200s. Competition for good farmland may also have prompted people to bond together to assert rights over the best fields.

Another important push was the onset of the Little Ice Age, a climatic phenomenon that led to cooler temperatures in the Northern Hemisphere. Although the height of the Little Ice Age was still around the corner, some evidence suggests that temperatures were falling during the thirteenth century. The environmental changes associated with this transition are not fully understood, but people living closest to the San Juan Mountains, to the northeast of Mesa Verde, were affected first. Growing food at these elevations is always difficult because of the short growing season. As the Little Ice Age progressed, farmers probably moved their fields to lower elevations, infringing on the lands of other farmers and pushing people together, thus contributing to the aggregations. Archaeologists identify a corresponding shift in populations toward the south and west toward Mesa Verde and away from higher elevations.

In the face of all these pushes, people in the Mesa Verde area had yet another reason to move into communal villages: the need for greater cooperation. Sharing and cooperation were almost certainly part of early Puebloan life, even for people living in largely independent single-household residences scattered across the landscape. Archaeologists find that even the most isolated residences during the eleventh and twelfth centuries obtained some pottery, and probably food, from some distance away, while major ceremonial events were opportunities for sharing food and crafts. Scholars believe that this cooperation allowed people to contend with a patchy environment in which precipitation and other resources varied across the landscape: if you produce a lot of food one year, you might trade it for pottery made by a distant ally who is having difficulty with crops—and the next year, the flow of goods might go in the opposite direction. But all of this appears to have changed thirteenth century. Although the climate remained as unpredictable as ever between one year and the next, it became much less locally diverse. In a bad year for farming, everyone was equally affected. No longer was it helpful to share widely. Instead, the most sensible thing would be for neighbors to combine efforts to produce as much food as possible, and thus aggregated towns were a sensible arrangement.

以上就是2012年10月27日托福阅读考试机经回忆的全部内容，各位考生可以以此作为参考，做好复习。最后预祝各位考生取得理想的成绩!



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