201401011阅读机经
机经词汇：
conceive(=imagine) V.构思，想象
stationary(=fixed )V稳定的，固定的
unrivaled(=unequaled) a.无可匹敌的，无与伦比的
drawback(=faults) n.弱点
respective(=separate) a.分开的，各自的
steadily(=continual) a.持续的
第一篇： 花粉传播
版本1: 主要讲的是花粉传播。
先讲花粉传播是繁殖基础。很多是通过动物传粉的，但是还有很多用风力，原因是范围更广。风力有缺点，不够准确，而且需要更多的花粉。一般在温带的森林里，植物品种少，会选择风力传粉，而热带地区种类多，就更多选择动物传粉，更有针对性。举了个例子，是站在屋顶上把要给朋友的信折起来之后扔出去，接不接得到。(有题)
然后讲风力传粉的植物，花更小，不起眼，花粉很多。(有题)
接着是说风力传粉的限制和要求颇多，比如风要够大，天气要干燥(不下雨)。
花粉的位置也很重要，在top，有举一种树。
版本2：关于用风来传播种子。
一些高纬度和温带地区用风传播种子。温带地区树种少，而且都是单一品种。所以风的传播怎么的都能到。就好像寄信给朋友，你朋友在山的那边的村庄，你爬上悬崖撒一把信下去，你朋友总会收到一封。但是热带地区的树种多而且分布广，就必须依靠动物进行特定方向的传播。
靠风传播的话植物就不需要类似明亮的颜色或者大的花朵之类的来吸引动物。有些花粉长在最高的枝上和叶上这样才能被风吹走。还说温带落叶的只有风大的时候植物才会产生花粉。
有些花粉小所以才能被吹得更远，但是也有可能卷入植物花粉接收部位附近的风里而不能被植物接收。
解析：
本文属于生物类里的植物类主题。本文以一个主题(花粉传播)展开数个并列的子主题(不同情况下的花粉传播)，每段讲述不同的气候与地理位置的花粉传播的方法。段落结构清晰，主题明确，对背景的描述会比较详尽，不会出现因为背景知识的生疏而严重影响对于文章理解的情况。需要注意的是，必须提前对相关类型的TPO文章的生词熟悉，尽量减少生词恐惧带来的内耗。推荐TPO26的Survival of Plants and Animals in Desert Conditions。
相关背景：
Survival of Plants and Animals in Desert Conditions
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.
The nature of plant life in deserts is also highly dependent on the fact that they have to adapt to the prevailing aridity. There are two general classes of vegetation: long-lived perennials, which may be succulent (water-storing) and are often dwarfed and woody, and annuals or ephemerals, which have a short life cycle and may form a fairly dense stand immediately after rain.
The ephemeral plants evade drought. Given a year of favorable precipitation, such plants will develop vigorously and produce large numbers of flowers and fruit. This replenishes the seed content of the desert soil. The seeds then lie dormant until the next wet year, when the desert blooms again.
The perennial vegetation adjusts to the aridity by means of various avoidance mechanisms. Most desert plants are probably best classified as xerophytes. They possess drought-resisting adaptations: loss of water through the leaves is reduced by means of dense hairs covering waxy leaf surfaces, by the closure of pores during the hottest times to reduce water loss, and by the rolling up or shedding of leaves at the beginning of the dry season. Some xerophytes, the succulents (including cacti), store water in their structures. Another way of countering drought is to have a limited amount of mass above ground and to have extensive root networks below ground. It is not unusual for the roots of some desert perennials to extend downward more than ten meters. Some plants are woody in type —an adaptation designed to prevent collapse of the plant tissue when water stress produces wilting. Another class of desert plant is the phreatophyte. These have adapted to the environment by the development of long taproots that penetrate downward until they approach the assured water supply provided by groundwater. Among these plants are the date palm, tamarisk, and mesquite. They commonly grow near stream channels, springs, or on the margins of lakes.
Animals also have to adapt to desert conditions, and they may do it through two forms of behavioral adaptation: they either escape or retreat. Escape involves such actions as aestivation, a condition of prolonged dormancy, or torpor, during which animals reduce their metabolic rate and body temperature during the hot season or during very dry spells.
Seasonal migration is another form of escape, especially for large mammals or birds. The term retreat is applied to the short-term escape behavior of desert animals, and it usually assumes the pattern of a daily rhythm. Birds shelter in nests, rock overhangs, trees, and dense shrubs to avoid the hottest hours of the day, while mammals like the kangaroo rat burrow underground.
Some animals have behavioral, physiological, and morphological (structural) adaptations that enable them to withstand extreme conditions. For example, the ostrich has plumage that is so constructed that the feathers are long but not too dense. When conditions are hot, the ostrich erects them on its back, thus increasing the thickness of the barrier between solar radiation and the skin. The sparse distribution of the feathers, however, also allows considerable lateral air movement over the skin surface, thereby permitting further heat loss by convection. Furthermore, the birds orient themselves carefully with regard to the Sun and gently flap their wings to increase convection cooling.#p#副标题#e#
第二篇： 油画的历史
版本一：本文主要讲油画的历史。
文章先说意大利其实不是第一个有油画的地方，第一个用油画来装饰教堂的是挪威。然后意大利的一个艺术家以为这是从德国传过的。然后意大利人发现这种东西还能用在玻璃上。挪威就是用在教堂的窗户上的。
然后威尼斯人最热衷的就是油画。在此之前威尼斯人对画画的热情还不及佛罗伦萨，但是X射线(X-ray)发现一个画家G的油画其实原版是一个妇人的画像，但是后来直接在上面画成了士兵。所以威尼斯人热衷油画是因为油画提供了冥想的色彩之类的，而却还能允许他们在创作的过程中更改思路。
接下来说油画一开始是画在木头之上的，后来画在帆布之上，这就给创作者更多的自由(freedom)来规划形状与大小(shape&size)，然后更容易话肖像(portrait)之类的。所以画家更容易place to place用帆布作画或者在画廊这样有模特的地方画画。
版本二：先给背景，油画最早其实是从德国，挪威传到意大利的，而不是意大利人发明的油画。
最早油画颜料是被一个木板画家发现的，后来还把它运用到了stained-glass上了，反复涂抹的颜料层会使颜色鲜艳，好看，但需要很长时间才能干。
在意大利，油画更多地为威尼斯人使用，威尼斯人比起佛罗伦萨人更在乎painting而不是drawing。
油画的发明方便了画家在painting的过程中修改画的内容。某画家的例子，某幅画通过x光发现原来底稿上是坐着的女人，最后画的是站着的士兵。
油画的诞生也促进了更portable的画布的广泛应用，不再使用木板做画。还讲到了人像的画作更方便，更多。
解析：本文围绕油画的发展历史这个主题展开论证。做题时需注意记录笔记，对于结构化阅读及最后一题的解答有很大好处。地理地质类主题是
相关背景：
The Birth of Photography
Perceptions of the visible world were greatly altered by the invention of photography in the middle of the nineteenth century. In particular, and quite logically, the art of painting was forever changed, though not always in the ways one might have expected. The realistic and naturalistic painters of the mid- and late-nineteenth century were all intently aware of photography—as a thing to use, to learn from, and react to.
Unlike most major inventions, photography had been long and impatiently awaited. The images produced by the camera obscura, a boxlike device that used a pinhole or lens to throw an image onto a ground-glass screen or a piece of white paper, were already familiar—the device had been much employed by topographical artists like the Italian painter Canaletto in his detailed views of the city of Venice. What was lacking was a way of giving such images permanent form. This was finally achieved by Louis Daguerre (1787-1851), who perfected a way of fixing them on a silvered copper plate. His discovery, the "daguerreotype," was announced in 1839.
A second and very different process was patented by the British inventor William Henry Talbot (1800-1877) in 1841. Talbot's "calotype" was the first negative-to-positive process and the direct ancestor of the modern photograph. The calotype was revolutionary in its use of chemically treated paper in which areas hit by light became dark in tone, producing a negative image. This "negative," as Talbot called it, could then be used to print multiple positive images on another piece of treated paper.
The two processes produced very different results. The daguerreotype was a unique image that reproduced what was in front of the camera lens in minute, unselective detail and could not be duplicated. The calotype could be made in series, and was thus the equivalent of an etching or an engraving. Its general effect was soft edged and tonal.
One of the things that most impressed the original audience for photography was the idea of authenticity. Nature now seemed able to speak for itself, with a minimum of interference. The title Talbot chose for his book, The Pencil of Nature (the first part of which was published in 1844), reflected this feeling. Artists were fascinated by photography because it offered a way of examining the world in much greater detail. They were also afraid of it, because it seemed likely to make their own efforts unnecessary.
Photography did indeed make certain kinds of painting obsolete—the daguerreotype virtually did away with the portrait miniature. It also made the whole business of making and owning images democratic. Portraiture, once a luxury for the privileged few, was suddenly well within the reach of many more people.
In the long term, photography's impact on the visual arts was far from simple. Because the medium was so prolific, in the sense that it was possible to produce a multitude of images very cheaply, it was soon treated as the poor relation of fine art, rather than its destined successor. Even those artists who were most dependent on photography became reluctant to admit that they made use of it, in case this compromised their professional standing.
The rapid technical development of photography—the introduction of lighter and simpler equipment, and of new emulsions that coated photographic plates, film, and paper and enabled images to be made at much faster speeds—had some unanticipated consequences. Scientific experiments made by photographers such as Eadweard Muybridge (1830-1904) and Etienne-Jules Marey (1830-1904) demonstrated that the movements of both humans and animals differed widely from the way they had been traditionally represented in art. Artists, often reluctantly, were forced to accept the evidence provided by the camera. The new candid photography—unposed pictures that were made when the subjects were unaware that their pictures were being taken—confirmed these scientific results, and at the same time, thanks to the radical cropping (trimming) of images that the camera often imposed, suggested new compositional formats. The accidental effects obtained by candid photographers were soon being copied by artists such as the French painter Degas.#p#副标题#e#
第三篇：板块漂移学说
版本一：
先是背景，早在15几几年就已经发现美洲和非洲的轮廓可以拼合。
有人提出是月球重力引力的原因使板块分离。被推翻，不然潮汐在地球自转的情况干扰下已经没了。
主角在研究部分地区的化石之后出书提出是板块漂移，但他少了解释漂移分裂的初始力。大部分人不赞同。
在巴西和非洲的地理学家否定其他全部，除了完全赞同板块漂移。植物化石，两栖动物化石，冰川构造都在大洋两岸完全一样。
提出盘古大陆。原来是一整块的，美洲和非洲是连在一起的很小的一块地方，后来才漂开的。
解析： 本文属于地质类文章，此前已经考过很多次了。本文主要讨论的是板块漂移学说，主旨明确，结构清晰，每段首句为topic sentence的可能性较高。大家在阅读文章之前可以先跳到最后一题(文章总结题)的位置看看那句对于文章总结的句子。对于大家从整体上把握文章的结构非常有帮助。推荐同学们先完成OG的文章Geology and Landscape。
相关背景：
Geology and Landscape
Most people consider the landscape to be unchanging, but Earth is a dynamic body, and its surface is continually altering-slowly on the human time scale, but relatively rapidly when compared to the great age of Earth (about 4,500 billion years). There are two principal influences that shape the terrain: constructive processes such as uplift, which create new landscape features, and destructive forces such as erosion, which gradually wear away exposed landforms.
Hills and mountains are often regarded as the epitome of permanence, successfully resisting the destructive forces of nature, but in fact they tend to be relatively short-lived in geological terms. As a general rule, the higher a mountain is, the more recently it was formed; for example, the high mountains of the Himalayas are only about 50 million years old. Lower mountains tend to be older, and are often the eroded relics of much higher mountain chains. About 400 million years ago, when the present-day continents of North America and Europe were joined, the Caledonian mountain chain was the same size as the modern Himalayas. Today, however, the relics of the Caledonian orogeny (mountain-building period) exist as the comparatively low mountains of Greenland, the northern Appalachians in the United States, the Scottish Highlands, and the Norwegian coastal plateau.
The Earth's crust is thought to be divided into huge, movable segments, called plates, which float on a soft plastic layer of rock. Some mountains were formed as a result of these plates crashing into each other and forcing up the rock at the plate margins. In this process, sedimentary rocks that originally formed on the seabed may be folded upwards to altitudes of more than 26,000 feet. Other mountains may be raised by earthquakes, which fracture the Earth's crust and can displace enough rock to produce block mountains. A third type of mountain may be formed as a result of volcanic activity which occurs in regions of active fold mountain belts, such as in the Cascade Range of western North America. The Cascades are made up of lavas and volcanic materials. Many of the peaks are extinct volcanoes.
Whatever the reason for mountain formation, as soon as land rises above sea level it is subjected to destructive forces. The exposed rocks are attacked by the various weather processes and gradually broken down into fragments, which are then carried away and later deposited as sediments. Thus, any landscape represents only a temporary stage in the continuous battle between the forces of uplift and those of erosion.
The weather, in its many forms, is the main agent of erosion. Rain washes away loose soil and penetrates cracks in the rocks. Carbon dioxide in the air reacts with the rainwater, forming a weak acid (carbonic acid) that may chemically attack the rocks. The rain seeps underground and the water may reappear later as springs. These springs are the sources of streams and rivers, which cut through the rocks and carry away debris from the mountains to the lowlands.
Under very cold conditions, rocks can be shattered by ice and frost. Glaciers may form in permanently cold areas, and these slowly moving masses of ice cut out valleys, carrying with them huge quantities of eroded rock debris. In dry areas the wind is the principal agent of erosion. It carries fine particles of sand, which bombard exposed rock surfaces, thereby wearing them into yet more sand. Even living things contribute to the formation of landscapes. Tree roots force their way into cracks in rocks and, in so doing, speed their splitting. In contrast, the roots of grasses and other small plants may help to hold loose soil fragments together, thereby helping to prevent erosion by the wind.