Passage 1 (重复NA20110805)
【主旨】Cell-theory
【内容】第一段：科学家Robert Hooke在1665年运用"单片镜"看到细胞的轮廓，Hooke用"单片镜"观察细胞轮廓比当时的"双片镜"更有优势(这里有考题：细节题，为什么用"单片镜"观察)。Hooke的历史地位在于他是看到"细胞"的第一人，并给这种结构命名为"cell",现在一直沿用，但是缺陷在于看到的只是"死细胞"--细胞死后的细胞壁留下的轮廓。
第二段：Anton van Leeuwenhoek第一次看到了活细胞，是从他的牙龈上刮下来细菌(bacteria)。但是他没有挑战错误的"传统理论"：生命从"无生命形式"发展而来(cell evolves from nonliving form and nothingness)。同样错误的理论是：完整的细胞可由Nucleus (细胞核)生长出membrane(细胞膜)和细胞壁。细胞难以被观察到有两大原因：1，技术不够成熟(technology);2. 错误理论的根深蒂固。
第三段：Theodor Schwann和Matthias Jakob Schleiden进一步观察细胞。他们共同观察了"动物"和"植物"的细胞，并得出细胞是""The cell is the fundamental element of organization，unit of structure and function"。Schleiden在显微镜(microscope)下观察到兰花植物(orchid plant)细胞,并在显微镜下也观察到其他动物细胞。两位科学家的共同结论是：细胞(cell)可以单独存在(existed),但是在更大的器官中(larger organisms)是living organism的一部分(这里有考题：这句话是"重述题")。他们共同确定了细胞理论。
第四段：英国科学家Robert Brown 完善了细胞理论，并成为细胞理论的先驱者。他的瞻前发现是：很多疾病(diseases)是从一个变异细胞(abnormal cell)演变而来，这在当时并没有被接纳，但是现代理论证明这是正确的。
参考文章：The cell was first seen by Robert Hooke in 1665. He examined (under a coarse, compound microscope) very thin slices of cork and saw a multitude of tiny pores that he remarked looked like the walled compartments a monk would live in. Because of this association, Hooke called them cells, the name they still bear. However, Hooke did not know their real structure or function. Hooke's description of these cells (which were actually non-living cell walls) was published in Micrographia. His cell observations gave no indication of the nucleus and other organelles found in most living cells.
The first person to make a compound microscope was Zacharias Jansen, while the first to witness a live cell under a microscope was Anton van Leeuwenhoek, who in 1674 described the algae Spirogyra and named the moving organisms animalcules, meaning "little animals". Leeuwenhoek probably also saw bacteria. Cell theory was in contrast to the vitalism theories proposed before the discovery of cells.
The idea that cells were separable into individual units was proposed by Ludolph Christian Treviranus and Johann Jacob Paul Moldenhawer. All of this finally led to Henri Dutrochet formulating one of the fundamental tenets of modern cell theory by declaring that "The cell is the fundamental element of organization".
The observations of Hooke, Leeuwenhoek, Schleiden, Schwann, Virchow, and others led to the development of the cell theory. The cell theory is a widely accepted explanation of the relationship between cells and living things. The cell theory states:
All living things or organisms are made of cells and their products.
New cells are created by old cells dividing into two.
Cells are the basic building units of life.
The cell theory holds true for all living things, no matter how big or small. Since according to research, cells are common to all living things, they can provide information about all life. And because all cells come from other cells, scientists can study cells to learn about growth, reproduction, and all other functions that living things perform. By learning about cells and how they function, you can learn about all types of living things. Cells are the building blocks of life
Credit for developing cell theory is usually given to three scientists: Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow. In 1839, Schwann and Schleiden suggested that cells were the basic unit of life. Their theory accepted the first two tenets of modern cell theory (see next section, below). However, the cell theory of Schleiden differed from modern cell theory in that it proposed a method of spontaneous crystallization that he called "free cell formation". In 1855, Rudolf Virchow concluded that all cells come from pre-existing cells, thus completing the classical cell theory. (Note that the idea that all cells come from pre-existing cells had in fact already been proposed by Robert Remak; it has been suggested that Virchow plagiarised Remak.)
Passage 2 (重复NA20111105)
【主旨】Wild Crops Domestication in Southwest Asia
【内容】描述了西南亚野生作物驯化(domestication)的艰难。
第一段：理解西南亚农业文化的发展，不可避免的要理解小麦(wheat)、大麦(Barley)的domestication过程。最早进行驯养化的野生作物是legume(这里有考题："推理题"：选项为豆荚legume不是理解西南亚农业文化必不可少野生作物作物--小麦、大麦才是)。 在西南亚驯养化过程中，pig的地位比cattle、sheep重要。
第二段：野生作物的驯养化艰难。早期农民发现，只有在很多条件共同满足下才能得到饱满的稻穗：如sunlight, water and soil。所以如果野生作物不能发展出适应恶劣环境或者各种环境的特征，农民只能在稻田里收割到很少的作物，并且scattered in the tract。
第三段：稻穗中有一个重要的结构是连接茎秆和穗头的部分的"柄"。通常野生作物的"柄"非常脆弱，风一吹或者动物一碰，穗头就会掉落，这给早期农民收割稻穗带来很大的麻烦。因为不能用sickle收割(镰刀太硬，碰落稻穗)。但是如果不用镰刀，收割作物是很困难的(这里有考题：插入提， 插入句中有sickle这个单词，只有前面这一句提到了sickle)。
第四段：另一个驯养化困难是：野生作物有坚硬的husk，以保护kernel不受frost and wind的侵袭。而人类的消化系统难以消化如此坚硬的外壳。还有一个困难是，野生作物的一株作物的麦穗只有两根，产量很低，现代驯养化一株作物的麦穗有六根，所以野生作物需要发展出多麦穗的特征。
第五段：野生作物只有发展出以上所说的所有驯养化特征，才值得农民大面积"劳动密集型"耕作。(这里有考题：重述题)。
参考文章：Plant Domestication
The earliest human attempts at plant domestication occurred in South-Western Asia. There is early evidence for conscious cultivation and trait selection of plants by pre-Neolithic groups in Syria: grains of rye with domestic traits have been recovered from Epi-Palaeolithic (c. 11,050 BC) contexts at Abu Hureyra in Syria, but this appears to be a localised phenomenon resulting from cultivation of stands of wild rye, rather than a definitive step towards domestication.
By 10,000 BC the bottle gourd (Lagenaria siceraria) plant, used as a container before the advent of ceramic technology, appears to have been domesticated. The domesticated bottle gourd reached the Americas from Asia by 8000 BC, most likely due to the migration of peoples from Asia to America.
History of Wheat
History
Wheat likely originated in the so-called Fertile Crescent of the Middle East, land which extended from Israel along the Mediterranean Sea north to southern Turkey and east to Iraq and the Persian Gulf. It was also probably native to southwestern Asia. Some of the earliest specimens have been discovered in Jordan, Syria, and Turkey. Early types of wheat have been excavated in Iraq, dating to over 11,000 B.C. Archaeological research indicates that wheat was being farmed in Egypt's Nile Valley since before 5,000 B.C., and also in China and India. Sumerians (in what is now southeastern Iraq) around 3100 B.C. wrote about both bread and beer made from wheat.
Geography
Archaeologists have determined that agriculture began there in the Fertile Crescent region, when people began growing wheat and other crops rather than foraging for them. Other ancient cultivated crops include barley, grapes, dates, and nuts. People in this region also were the first to herd goats, pigs, and sheep. It took only a few centuries for people to do away with hunting and gathering as their main source of food, after many thousands of years obtaining food that way.
The first cultivated crop in the Americas was maize in Mexico, which was not purposely planted in large amounts until around 4,000 B.C..
Significance
Wheat is very significant in history because it is one of the crops which transformed hunter-gatherers into farmers. People had long gathered wheat where it grew wild, but with agriculture, a more dependable food supply was created. This in turn made life easier with more free time, and people were able to turn more attention to other pursuits such as creating textiles and pottery, and doing woodworking and making tools.
Agriculture, along with herding of animals, allowed for the growth of large permanent communities, as well as a privileged elite class in cities. It also resulted in battles for productive areas, evidenced early in the Bible after Moses led the Israelites to the promised land, where they then had to fight to get it away from the people already living there.
Egypt was the largest producer of wheat in ancient times, with enormous harvests unequaled even today. It became the basis of the nation's economy. Egyptians first created raised yeast breads as a contrast to the unleavened bread which had been the only type available before.
The objectives of wheat domestication
-To produce 'non-shattering' varieties that have seeds that are not lost by breaking off the plant before harvest. Wild grasses are adapted to dispersing their seeds by releasing them once ripe but grasses under cultivation, such as wheat, need to have seeds that are retained and only break off during the threshing process. Selection of non-shattering varieties would have occurred quickly once cultivation started, as it was only these plants that would have been successfully harvested.
-To produce large, plump seeds.
-To produce more seeds per plant by increasing the number of fertile flowers (termed florets in grasses).
-To produce 'free-threshing' or 'naked' varieties where the husk round the seed comes off during threshing. All's that needs to be done after threshing is for the grain to be winnowed so that the empty husks (i.e. chaff) are blown away from the seeds. Wild varieties of wheat are hulled - i.e. the seeds are covered by a tough husk that stays round the seed once it has been threshed. To get this husk off the seed, it has to be pounded in some way which is more laborious than winnowing the husks away and means the grain is broken and less suitable for storing.
-To produce seeds that germinate together. Wild forms are adapted to delay germination until there are suitable conditions and to vary the timing of germination so that seeds do not grow up and die altogether during a season of erratic and poor rainfall.
Passage 3 (重复NA20111119)
【主旨】Red-billed Quelea
【内容】讲述红嘴奎利亚雀适应(adaptation)生存环境的艰难过程。
第一段：除了鸟类学家(ornithologist)和当地人(people see the birds in the native habitat)看得到红嘴奎利亚雀，世界上其他人很少听到"红嘴奎利亚雀"的名字，但是根据它的实际存在数量(several billions)可以得知"红嘴奎利亚雀"是the most common bird in the world。
第二段：红嘴奎利亚雀身体小巧，要适应多变的生存环境非常艰难，但是它却发展出很多特征。红嘴奎利亚雀以食青草(annul green grass)为生。实际上，她是以食用青草的种子为生(这里有考题：插入题)。但是"草种"随着季节的变化有多有少，所以以食用草种为生的动物必须衍生出特殊的习性。举例：啮齿类动物(rodent)在冬天储存食物就是适应寒冬食物短缺的困难("修辞目的题"：作者为什么提到啮齿类动物?)。红嘴奎利亚雀没有这样的特性，但是有自己的特征，分两方面：(1)the end of dry season，红嘴奎利亚雀会吃很多食物gain weight，以便抵御食物短缺;(2)干旱季节过后紧接着是the early of the rain season，这个时候红嘴奎利亚雀不能吃草种，因为草种都在发芽,发芽的草种是不能吃的，所以红嘴奎利亚雀会飞往其他可食用的田地。这个食物短缺的过程将持续6-8 weeks(这里有考题：推理题：从文中6-8周我们可以推理出什么?答案：青草利用者6-8周发芽长出青草和新的种子)。
第三段：所以红嘴奎利亚雀的生活基本上就是从"食物短缺"的habitat不断寻找suitable和有食物的田地的过程。但是6-8周后，红嘴奎利亚雀会回到当初雨季早期青草发芽的地方，因为此时青草肥美，草种丰盛，于是所有的红嘴奎利亚雀开始了"繁殖周期"(breeding cycle)，这个周期很短，因为气候多变，但是规模宏大，令人惊叹。有时在同一天同一个区域能看到millions of Red-billed Quelea hatch in millions of nest，蔚为壮观。更壮观的是，当小鸟破壳而出时，所有的蛋壳一起掉落像"下雪"一样(原句：the fall of the eggshell and the subsequent dropping of the shell are likened to be snow fall)。而且红嘴奎利亚雀的繁殖周期可以"同步"(synchronize)。如果前面的雨季还没有结束，那么所有鸟的"繁殖周期"就同时缩短，短的可达几天。
第四段：红嘴奎利亚雀被认为是农作物的"害鸟"。因为红嘴奎利亚雀连艰难的生存环境和难吃的野生作物都能适应，那么农民大面积种植粮食作物就成了他们很好的食物。又由于数量众多，红嘴奎利亚雀在世界范围内被认为是最大的"害鸟。"
参考文章：Red-billed Quelea
The Red-billed Quelea (Quelea quelea) is the world's most abundant wild bird species, with an estimated adult breeding population of 1.5 billion pairs. Some estimates of the overall population have been as large as 10 billion. The entire population is found in sub-Saharan Africa and is generally absent from deeply forested regions and the southern reaches of South Africa. It is a small passerine bird of the weaver family Ploceidae.
Habits
Red-billed Quelea live and breed in huge flocks which can take up to 5 hours to fly past. They live mostly in steppe and savanna regions, but do not avoid human settlements. While foraging for food they may fly large distances each day without tiring. Their life expectancy is two to three years.
Reproduction
Breeding is localized and erratic but often colonies include tens of thousands to millions of pairs. The breeding season begins with the seasonal rains, which come at different times in different parts of their range - starting at the north-western edge around the beginning of November. The breeding males first weave half-complete ovoid nests from grass and straw. After the female has examined the construction and the mating has occurred, both partners complete the weaving of the nest. The female lays two to four light blue eggs, and incubates them for twelve days. After the chicks hatch, they are nourished for some days with caterpillars and protein-rich insects. After this time parents change to feeding the nestlings mainly seeds. The young birds fledge and become independent enough to leave their parents after approximately two weeks in the nest. They are sexually mature after just one year, but many birds die before reaching this stage and males may weave nests that go unused if the female dies.
Food
The food of the Red-billed Quelea consists of annual grasses, seeds and grain. As soon as the sun comes up, they come together in their huge flocks and co-operate in finding a suitable feeding place. After a successful search, they settle rapidly and can cause serious damage to crops. In the middle part of the day they rest in shady areas near water and preen. Birds seem to prefer drinking at least twice a day. In the evening they once again fly in search of food.
Enemies and population control
Being such a considerable part of the savanna biomass, Red-billed Quelea flocks and colonies attract huge numbers and diverse types of predators and scavengers. Birds known to live extensively off queleas include herons, storks, raptors, owls, hornbills, rollers, kingfishers, shrikes and corvids. Additionally, snakes, lizards and several types of mammals, especially rodents and small carnivores, are regular predators.
They are regarded as pests by farmers because they can eliminate fields in a short period of time. Due to the numbers and localized decimation of cereal crops, control actions have been undertaken. As many as 150-180 million birds have been killed but this appeared to have no effect on the overall quelea population and only temporary relief from crop damage. Unfortunately, many non-target birds appeared to have also been killed in these control operations and may have had severe population deprivations as a result