托福真题回忆 丨2021年11月20日 托福考试详细机经
Pastoralism in Ancient Inner Eurasia
Pastoralism is a lifestyle in which economic activity is based primarily on livestock. Archaeological evidence suggests that by 3000 B.C., and perhaps even earlier, there had emerged on the steppes of Inner Eurasia the distinctive types of pastoralism that were to dominate the region's history for several millennia. Here, the horse was already becoming the animal of prestige in many regions, though sheep, goats, and cattle could also play a vital role. It is the use of horses for transportation and warfare that explains why Inner Eurasian pastoralism proved the most mobile and the most militaristic of all major forms of pastoralism. The emergence and spread of pastoralism had a profound impact on the history of Inner Eurasia, and also, indirectly, on the parts of Asia and Europe just outside this area. In particular, pastoralism favors a mobile lifestyle, and this mobility helps to explain the impact of pastoralist societies on this part of the world.
The mobility of pastoralist societies reflects their dependence on animal-based foods. While agriculturalists rely on domesticated plants, pastoralists rely on domesticated animals. As a result, pastoralists, like carnivores in general, occupy a higher position on the food chain. All else being equal, this means they must exploit larger areas of land than do agriculturalists to secure the same amount of food, clothing, and other necessities. So pastoralism is a more extensive lifeway than farming is. However, the larger the terrain used to support a group, the harder it is to exploit that terrain while remaining in one place. So, basic ecological principles imply a strong tendency within pastoralist lifeways toward nomadism (a mobile lifestyle). As the archaeologist Roger Cribb puts it, “The greater the degree of pastoralism, the stronger the tendency toward nomadism.” A modern Turkic nomad interviewed by Cribb commented: "The more animals you have, the farther you have to move."
Nomadism has further consequences. It means that pastoralist societies occupy and can influence very large territories. This is particularly true of the horse pastoralism that emerged in the Inner Eurasian steppes, for this was the most mobile of all major forms of pastoralism. So, it is no accident that with the appearance of pastoralist societies there appear large areas that share similar cultural, ecological, and even linguistic features. By the late fourth millennium B.C., there is already evidence of large culture zones reaching from Eastern Europe to the western borders of Mongolia. Perhaps the most striking sign of mobility is the fact that by the third millennium B.C., most pastoralists in this huge region spoke related languages ancestral to the modern Indo-European languages. The remarkable mobility and range of pastoral societies explain, in part, why so many linguists have argued that the Indo-European languages began their astonishing expansionist career not among farmers in Anatolia (present-day Turkey), but among early pastoralists from Inner Eurasia. Such theories imply that the Indo-European languages evolved not in Neolithic (10,000 to 3,000 B.C.) Anatolia, but among the foraging communities of the cultures in the region of the Don and Dnieper rivers, which took up stock breeding and began to exploit the neighboring steppes.
Nomadism also subjects pastoralist communities to strict rules of portability. If you are constantly on the move, you cannot afford to accumulate large material surpluses. Such rules limit variations in accumulated material goods between pastoralist households (though they may also encourage a taste for portable goods of high value such as silks or jewelry). So, by and large, nomadism implies a high degree of self-sufficiency and inhibits the appearance of an extensive division of labor. Inequalities of wealth and rank certainly exist, and have probably existed in most pastoralist societies, but except in periods of military conquest, they are normally too slight to generate the stable, hereditary hierarchies that are usually implied by the use of the term class. Inequalities of gender have also existed in pastoralist societies, but they seem to have been softened by the absence of steep hierarchies of wealth in most communities, and also by the requirement that women acquire most of the skills of men, including, often, their military skills.
Early life-forms and Earth’s Atmosphere
Why has life flourished on Earth? This question has a two-part answer. First, Earth has been a cradle for life because of its position relative to the Sun. second, once life began on Earth, simple early life-forms (photosynthetic bacteria) slowly but inexorably altered the environment in a manner that not only maintained life but also paved the way for later, complex life-forms. These changes allowed later organisms to evolve and thrive. Humans and other higher organisms owe their life-supporting environment to these early life-forms.
Earth’s earliest atmosphere contained several gases: hydrogen, water vapor, ammonia, nitrogen, methane, and carbon dioxide, but no oxygen. Gas mixtures emitted from present-day volcanoes resemble this early atmosphere, suggesting its origin from volcanic eruptions. In Earth’s earliest
atmosphere, methane and carbon dioxide occurred at much higher levels than at present—a circumstance that was favorable for early life. Methane and carbon dioxide are greenhouse gases that warm atmospheres by retarding loss of heat to space. These two gases kept Earth warm during the Sun’s early history, when the Sun did not burn as brightly as it now does. (An early dim period, with later brightening, is normal for stars of our Sun’s type.)
Earth’s modern atmosphere, which is 78 percent nitrogen gas, 21 percent oxygen, and about 1 percent argon, water vapor, ozone, and carbon dioxide, differs dramatically from the earliest atmosphere just described. The modern atmosphere supports many forms of complex life that would not have been able to exist in Earth’s first atmosphere because the oxygen level was too
low. Also, if atmospheric methane and carbon dioxide were as abundant now as they were in Earth’s earliest atmosphere, the planet’s temperature would likely be too hot for most species living today. How and when did the atmosphere change?
The answer to this riddle lies in the metabolic activity of early photosynthetic life-forms that slowly but surely transformed the chemical composition of Earth’s atmosphere. Some of these early organisms were photosynthetic relatives of modern cyanobacteria (blue-green bacteria). In
the process of photosynthesis, carbon dioxide gas combined with water yields oxygen. In Earth’s early days, all over the planet countless photosynthetic bacteria performed photosynthesis. Together, these ancient bacteria removed massive amounts of carbon dioxide from Earth’s atmosphere by converting it to solid organic carbon. These ancient bacteria also released huge quantities of oxygen into the atmosphere. Other ancient bacteria consumed methane, greatly reducing its amount in the atmosphere. When our Sun later became hotter, the continued removal of atmospheric carbon dioxide and methane by early bacteria kept Earth’s climate from
becoming too hot to sustain life. Modern cyanobacteria still provide these valuable services today.
The bacterial oxygen release improved conditions for life in two ways. First, oxygen is essential for the metabolic process known as cell respiration that allows cells to efficiently harvest energy from organic food. Second, oxygen in the upper atmosphere reacts to form a protective shield of ozone. Earth is constantly bombarded by harmful ultraviolet (UV) radiation from the Sun. Today, Earth’s upper-atmosphere ozone shield absorbs enough UV to allow diverse forms of life to survive. But because early Earth lacked oxygen in its atmosphere, it also lacked a protective ozone barrier. As a result, early life on Earth was confined to the oceans, where the water absorbed the UV radiation. Only after oxygen released by ancient bacteria drifted up into the
upper atmosphere and reacted with other oxygen molecules to form a protective layer of ozone could life flourish at the surface and on the land. The absence of an oxygen atmosphere on Mars and other planets in our solar system means that these planets also lack an ozone shield that would protect surface-dwelling life from UV radiation. The surface of Mars is bombarded with deadly radiation; if any life exists on Mars, it would almost certainly be subterranean.
Costs and Benefits of Social Life
Many think that the reason so many animals live with others of their species is that social creatures are higher up the evolutionary scale and so are better adapted and leave more offspring than do animals that live solitary lives. However, in each and every species, generation after generation, relatively social and relatively solitary types compete unconsciously with one another in ways that determine who leaves more offspring on average. In some species, the more social individuals have won out, but in a large majority, it is the solitary types that have consistently left more surviving descendants on average.
But how can living alone ever be superior to living together? Under some conditions, a cost-benefit comparison favors solitary life over a more social existence. For example, among most social species, animals have to expend time and energy competing for social status. Those that do not occupy the top positions regularly have to signal their submissive state to their superiors if they are to be permitted to remain in the group. This can take up a major share of a social subordinate's life. In fact, even in small social groups there are both subtle competition and not-so-subtle competition.
Social groups also offer opportunities for reproductive interference. Breeding males that live in close association with more attractive rivals may lose their mates to these individuals. In addition, sociality has two other potential disadvantages. The first is heightened competition for food, which occurs in animals as different as colonial fieldfares (a kind of songbird) and groups of lions, whose females are often pushed from their food by hungry males. The second is increased vulnerability to parasites and disease, which plague social species of all sorts. While it is true that some social animals have evolved special responses designed to combat parasites and disease, those responses can only reduce, but cannot totally eliminate, the damage caused by those threats, and the responses may even carry their own costs. Thus, honeybees warm their hives in response to an infestation by a fungal pathogen, which apparently helps kill the heat-sensitive fungus, but at the price of time and energy expended by the heat-producing workers.
If social living carries a heightened risk of infection, then the larger the group, the greater the risk. This prediction holds for cliff swallows, which pack their nests side by side in colonies composed of anywhere from a handful of birds to several thousand pairs. The more swallows nesting together, the greater the chance that at least one bird will be infested with swallow bugs, which can then readily spread from one nest to another.
The parasites and fungi that make life miserable for swallows and other social creatures demonstrate that if sociality is to evolve, the asorted costs of living together must be outweighed by compensatory benefits. Cliff swallows may join others to take advantage of the improved foraging that comes from following companions to good feeding sites, while other animals, such as male imperial penguins, save thermal energy by huddling shoulder to shoulder during the brutal Antarctica winter. Still others, such as lionesses, join forces to fend off enemies of their own species.
The most widespread fitness benefit for social animals, however, probably is improved protection against predators. Many studies have shown that animals in groups gain by reducing the individual risk of being captured, or by spotting danger sooner, or by attacking their enemies in groups. Males in nesting colonies of bluegill sunfish cooperate in driving egg-eating bullhead catfish away from their nests at the bottom of a freshwater lake. While bluegills have adopted social behavior to avoid predation, closely related species that nest alone have evolved means to protect themselves while nesting alone. Thus, the solitary pumpkinseed sunfish, a member of the same genus as the bluegill, has powerful biting jaws and so can repel egg-eating enemies on its own, whereas bluegills have small, delicate mouths good only for inhaling small, soft-bodied insect larvae. Pumpkinseed sunfish are in no way inferior to or less well adapted than bluegills because they are solitary; they simply gain less through social living, which makes solitary nesting the adaptive tactic for them.
The Origin of Earth's Atmosphere
In order to understand the origin of Earth's atmosphere, we must go back to the earliest days of the solar system, before the planets themselves were formed from a disk of rocky material spinning around the young Sun. This material gradually coalesced into lumps called planetesimals as gravity and chance smashed smaller pieces together, a chaotic and violent process that became more so as planetesimals grew in size and gravitational pull. Within each orbit, collisions between planetesimals generated immense heat and energy. How violent these processes were is suggested by the odd tilt and spin of many of the planets, which indicate that each of the planets was, like a billiard ball, struck at some stage by another large body of some kind. Visual evidence of these processes can be seen by looking at the Moon. Because the Moon has no atmosphere, its surface is not subject to erosion, so it retains the marks of its early history. Its face is deeply scarred by millions of meteoric impacts, as you can see on a clear night with a pair of binoculars. The early Earth did not have much of an atmosphere. Before it grew to full size, its gravitational pull was insufficient to prevent gases from drifting off into space, while the solar wind (the great stream of atomic particles emitted from the Sun) had already driven away much of the gaseous material from the inner orbits of the solar system. So we must imagine the early Earth as a mixture of rocky materials, metals, and trapped gases, subject to constant bombardment by smaller planetesimals and without much of an atmosphere.
As it began to reach full size, Earth heated up, partly because of collisions with other planetesimals and partly because of increasing internal pressures as it grew in size. In addition, the early Earth contained abundant radioactive materials, also a source of heat. As Earth heated up, its interior melted. Within the molten interior, under the influence of gravity, different elements were sorted out by density. By about 40 million years after the formation of the solar system, most of the heavier metallic elements in the early Earth, such as iron and nickel, had sunk through the hot sludge to the center, giving Earth a core dominated by iron.This metallic core gives Earth its characteristic magnetic field, which has played an extremely important role in the history of our planet.
As heavy materials headed for the center of Earth, lighter silicates (such as the mineral quartz) drifted upward. The denser silicates formed Earth's mantle, a region almost 3,000 kilometers thick between the core and the crust. With the help of bombardment by comets, whose many impacts scarred and heated Earth's surface, the lightest silicates rose to Earth's surface, where they cooled more rapidly than the better-insulated materials in Earth's interior.
These lighter materials, such as the rocks we call granites, formed a layer of continental crust about 35 kilometers thick. Relative to Earth as a whole, this is as thin as an eggshell. Seafloor crust is even thinner, at about 7 kilometers; thus, even continental crust reaches only about 1/200th of the way to Earth's core. Much of the early continental crust has remained on Earth's surface to the present day.
The lightest materials of all, including gases such as hydrogen and helium, bubbled through Earth's interior to the surface. So we can imagine the surface of the early Earth as a massive volcanic field. And we can judge pretty well what gases bubbled up to that surface by analyzing the mixture of gases emitted by volcanoes. These include hydrogen, helium, methane, water vapor, nitrogen, ammonia, and hydrogen sulfide. Other materials, including large amounts of water vapor, were brought in by cometary bombardments. Much of the hydrogen and helium escaped; but once Earth was fully formed, it was large enough for its gravitational field to hold most of the remaining gases, and these formed Earth's first stable atmosphere.
Washington D.C. art school – abstract painting
When people acquire a new product, some prefer to read the directions in the manual to understand how it works. Other people prefer to experiment with the product to try to figure it out on their own. Which do you prefer and why?
Generally speaking, I prefer to read manuals to learn how a new product works since figuring it out by myself can be really time-consuming.
It goes without saying that the more time I spend testing the product, the less attention I will pay to my studies, which will inevitably compromise my academic performance.
You know, the competition at school is fierce and brutal, one must work extraordinarily hard to stay ahead of the game, otherwise they will be outperformed.
But there are other times like when the directions in the manuals are written in languages that I cannot understand, like in Korean or Spanish, then I will have to try the product by myself. I mean, what else can I do?
听力不同意。1. 两天时间太短，这些技能和知识很难，所以学不会。2. 学生根本没必要学，他们不开自己的公司，因为现在公司会雇佣专业的人才。
Franklin's sailors died and were found lead poisoned in their bodies. Some people think it was because the canned food.
-lead not in contact with food，铅是用于罐头表面，而食物在里面，不会受到其影响
-no other report，当时的其他船员也都会食用这种罐头，假如真的因为罐头不可能只有这一例中毒案件
-one other possible result，船上的净水系统的管道是铅做的，所以有可能是净水系统出问题了
-船上的净水系统是为机器提供水的，并没有用于 drinking and cooking，饮用水及做饭用的水是特殊分开储藏的，因为他们知道盐水会毁掉他们的身体，所以不可能是管道的铅进入人体
Both the reading and the listening discuss about the reason why Franklin’s sailors died. The reading argues that the lead in canned food is not the cuplrit, while the lecturer casts doubt on this viewpoint.
First, as the reading suggests, lead is only used in the surface while the food is inside of the can, therefore it could not impose any effect on the food. However, the listening points out since the can-producing workers are busy and tired, the lead could be leaked into the food because workers’ carelessness and fatigue.
Second, the reading mentions that there is no other report If it is lead causing the poisonous process, other eaters could have reported more than one case. On the contrary, the lecturer refutes that since nobody got checked regarding the lead concentration, it is hard to report. The typical symptom of leading poisoning is headache, which is so common that it would be construed as the symptoms of other diseases. Other workers might have accumulated ample concentrations of lead that have not reached the tipping point of death.
Third, the reading passage suggests another possible contributor is the water cleaning system made of lead. On the other hand, the lecturer claims that the cleaning system is there for the machine and not for drinking or cooking. Cooking and drinking water are separately stored because sailors are fully aware of the detriments of drinking saulty water. Therefore, it is not likely that the lead of the pipes caused the problem.
【独立写作】（青少年类/社会生活类）Do you agree or disagree with the following statement? It is better to take risks and explore new things when you are older rather than when you are younger.Use specific reasons and examples to support your answer. （同2021.05.18考题）
Conventional wisdom generally believes that it is easier for young people to be exposed to innovative ideas and new concepts so that they can catch up with the current news and most up to date information. Elders, on the other hand, are supposed to relax and enjoy their retirement to the fullest extent. However, I have a totally different perspective on this issue and tend to believe that older people need to explore new things more than young people.
Admittedly, young people are generally more healthy and energetic than the elders, hence it is more likely for them to come up with new ideas and perspectives than elders. Indeed, as we can tell that professionals in different fields like scientists, business men, lawyers tend to have be more competitive and sharp when they are at a young age, actually, research shows that the average age of billionaires is well below 40. Nonetheless, it is more important for elders to stay touch with the latest trend and continue their lifelong learning. First and foremost, continued learning makes it possible for elders to stay in touch with the currents and build a deeper connection with younger family members. The only thing that doesn't change in today's world is change itself, new electronic gadgets, innovative treatment to cure incurable diseases, creative business ideas and approaches that are unthinkable in the past, you name it. It can be disastrous if elders stop being an active learner and retreat to the primitive mindset. For instance, young people are fond of new electronic devices like ipad, iphone and stuff, and they use these gadgets to stay in touch with their peers and families. If a grandpa has not even heard of twitter or instagram, it will be impossible for the two generations to stay connected.
Additionally, a host of research done by a world famous psychiatrist show that elders who give up learning and have no access to new ideas tend to suffer from dementia and Alzheimer. On the other hand, other search shows that elders who keep learning will stay in touch with the world and are more healthier both physically and mentally. Based on my personal experience, I find elders around who are willing to learn and embrace new things are less dependent on their families and tend to be better connected with their children and grandchildren. Plus, they are more creative and productive when they access their frontal lobe and avoid their primitive mindset. Staying active and keeping exploring new things make it possible for seniors to seek for the true meaning and value of life, which in turn will inspire and motivate younger generation to take risks and accept challenges in life.
In a nutshell, we can safely draw the conclusion that it is better for elders to take risks and explore in new endeavors than the younger generations since it helps elders reconnect with their families and makes them more independent, productive and inspirational.