Passage 1

　　1890’s之前，美国尚未经历City Beautiful Movement，除却极个别的Washington D.C，当时的城市规划最大的特点就是——no urban planning.

　　影响美国人民住址选定的几个因素主要为：economics，preference to live individually, etc.

　　当时的两大特点为：1.随着移民风潮(migration)和大量农村人口涌入城市，城市对于住房的要求开始增长;2.大量城市人口(urbanites)考虑到城市居住诸多隐患，迁移乡村。

　　主要的城市居住弊端为，大量建筑材料易燃、楼距太近、城市明火使用导致火灾频发;排水系统不完善，进而啮齿类动物传播疾病，危及居民健康。

　　总而言之，当时的城市规划相当不完善，没有统一的政府监管，基础设施建设相当落后。

　　解析：本篇文章典型的历史类文章，讲城市的发展。重点讲了当时人们居住生活的特点，影响人们居住模式的因素，该居住模式带来的影响三大方面的内容。相关内容大家参照以下文章内容理解。

　　Rise of Industrial America

　　Between 1880 and 1900, cities in the United States grew at a dramatic rate. Owing most of their population growth to the expansion of industry, U.S. cities grew by about 15 million people in the two decades before 1900. Many of those who helped account for the population growth of cities were immigrants arriving from around the world. A steady stream of people from rural America also migrated to the cities during this period. Between 1880 and 1890, almost 40 percent of the townships in the United States lost population because of migration.

　　Industrial expansion and population growth radically changed the face of the nation's cities. Noise, traffic jams, slums, air pollution, and sanitation and health problems became commonplace. Mass transit, in the form of trolleys, cable cars, and subways, was built, and skyscrapers began to dominate city skylines. New communities, known as suburbs, began to be built just beyond the city. Commuters, those who lived in the suburbs and traveled in and out of the city for work, began to increase in number.

　　Many of those who resided in the city lived in rental apartments or tenement housing. Neighborhoods, especially for immigrant populations, were often the center of community life. In the enclave neighborhoods, many immigrant groups attempted to hold onto and practice precious customs and traditions. Even today, many neighborhoods or sections of some of the great cities in the United States reflect those ethnic heritages.

　　During the final years of the 1800s, industrial cities, with all the problems brought on by rapid population growth and lack of infrastructure to support the growth, occupied a special place in U.S. history. For all the problems, and there were many, the cities promoted a special bond between people and laid the foundation for the multiethnic, multicultural society that we cherish today

　　City Beautiful Movement

　　The City Beautiful Movement was a reform philosophy of North American architecture and urban planning that flourished during the 1890s and 1900s with the intent of introducing beautification and monumental grandeur in cities. The movement, which was originally associated mainly with Chicago, Cleveland, Detroit, and Washington, D.C. promoted beauty not only for its own sake, but also to create moral and civic virtue among urban populations.[1] Advocates of the philosophy believed that such beautification could thus promote a harmonious social order that would increase the quality of life.

　　Origins and Effect

　　The movement began in the United States in response to crowding in tenement districts, a consequence of high birth rates, increased immigration and consolidation of rural populations into cities. The movement flourished for several decades, and in addition to the construction of monuments, it also achieved great influence in urban planning that endured throughout the 20th century, in particular in regard to the later creation of housing projects in the United States. The "Garden City" movement in Britain influenced the contemporary planning of some newer suburbs of London, and there was cross-influence between the two aesthetics, one based in formal garden plans and urbanization schemes and the other, with its "semi-detached villas" evoking a more rural atmosphere.

　　Passage 2

　　Topic: Honeybees Juvenile Hormone

　　在蜜蜂种群当中，根据年龄的不同，承担不同的任务，这种现象称之为“age polytheism”。比如，年幼的蜜蜂，一般在蜂巢工作，feed the queen and pupae;年长一点的蜜蜂，负责找食物(forage)和存储食物。分工不同的具体解释为，特定举动的频率会比较高，而并非彻底add or eliminate to the total number of the tasks they perform(此处考点)。

　　研究表明，如此的分工，主要是由于蜜蜂当中一种叫做Juvenile Hormone的物质进行控制。Juvenile Hormone随着蜜蜂年龄的增长，分泌的速率提升，JH刺激蜜蜂大脑当中叫做mushroom区域逐渐增大，导致最后行为的不同。

　　实验验证，摘除蜜蜂分泌JH的区域，人工注射JH类似物，能够使蜜蜂转变行为方式。

　　解析：本篇文章是典型关于动物行为的分析类文章。具体的文章结构应为提出一个现象：“在蜜蜂种群当中，根据年龄的不同，承担不同的任务，这种现象称之为“age polytheism”之后提出结论：“Juvenile Hormone的物质进行控制”。最后实验验证结论“摘除蜜蜂分泌JH的区域，人工注射JH类似物，能够使蜜蜂转变行为方式”的三部分。相应背景知识请大家参照以下内容把握。

　　Juvenile hormone

　　Juvenile hormones (JHs) are a group of acyclic sesquiterpenoids that regulate many aspects of insect physiology. JHs regulate development, reproduction, diapause, and polyphenisms.

　　In insects, JH (formerly called neotenin) refers to a group of hormones, which ensure growth of the larva, while preventing metamorphosis. Because of their rigid exoskeleton, insects grow in their development by successively shedding their exoskeleton (a process known as molting).

　　Juvenile hormones are secreted by a pair of endocrine glands behind the brain called the corpora allata. JHs are also important for the production of eggs in female insects.

　　JH was discovered in 1965 and the molecular structure solved in 1967.

　　Most insect species contain only juvenile hormone (JH) III. To date JH 0, JH I, and JH II have been identified only in the Lepidoptera (butterflies and moths). The form JHB3 (JH III bisepoxide) appears to be the most important JH in the Diptera, or flies.Certain species of crustaceans have been shown to produce and secrete methyl farnesoate, which is juvenile hormone III lacking the epoxide group. Methyl farnesoate is believed to play a role similar to that of JH in crustaceans

　　Juvenile hormones in honey bees

　　There is a complex interaction between JH, the hormone ecdysone and vitellogenin. In the development stage, as long as there is enough JH, the ecdysone promotes larva-to-larva molts. With lower amounts of JH, ecdysone promotes pupation. Complete absence of JH results in formation of the adult. In adult honey bees, JH and Vitellogenin titers in general show an inverse pattern.

　　JH titers in worker honey bees progressively increase through the first 15 or so days of the worker's life before the onset of foraging. During the first 15 days, workers perform tasks inside the hive, such as nursing larvae, constructing comb, and cleaning cells. JH titers peak around day 15; workers this age guard, remove dead bees from the colony, and fan at the colony entrance to cool the nest. Aggressiveness of guard bees is correlated with their blood JH levels. Even though guards have high JH levels, their ovaries are relatively undeveloped.Although, JH does not activate foraging. Rather it is involved in controlling the pace at which bees develop into foragers.

　　Vitellogenin titers are high at the beginning of adult life and slowly decrease.

　　JH has been known to be involved in the queen-worker caste differentiation during the larval stage.The unique negative relationship between JH and Vitellogenin may be important to the understanding of queen longevit

　　Passage 3

　　南美洲太平洋东岸的居民，每年都能迎来由南极洲方向洋流涌向赤道，在季风共同作用下，深层富含营养的冷水涌向海表层，带来大量的鳀鱼(anchovies)。但特定年份，海水异常温暖，持续2-3个月，因为发生在耶稣降临的月份周围，所以被称之为“圣婴(El Niño)现象”。

　　Gilbert Walker研究太平洋东岸和西岸气压发现了“跷跷板效应(Seesaw Effect)”，东岸气压高，则西岸气压低;反之亦然，该现象与厄尔尼诺有着千丝万缕的关系，所以合称——El Niño-Southern Oscillation。

　　回溯15世纪，西班牙人的各种记录，厄尔尼诺之前每隔6年发生一次，近年来有频率上升的趋势，每隔2年发生一次;且强度逐年增高，比如美国遭受暴雨侵袭等。

　　解析：本篇文章主要讲厄尔尼诺现象的影响，厄尔尼诺现象所带来的影响，以及该气候现象发生的频率等三大方面的主要内容。属于自然科学类文章中较为典型的文章结构类型，相应背景知识请大家阅读下面的文章了解

　　El Niño-Southern Oscillation

　　Definition

　　El Niño is defined by prolonged differences in the Pacific Ocean sea surface temperatures when compared with the average value. The accepted definition is a warming or cooling of at least 0.5°C (0.9°F) averaged over the east-central tropical Pacific Ocean. Typically, this anomaly happens at irregular intervals of two to seven years, and lasts nine months to two years.The average period length is five years. When this warming or cooling occurs for only seven to nine months, it is classified as El Niño/La Niña "conditions"; when it occurs for more than that period, it is classified as El Niño/La Niña "episodes".

　　The first signs of an El Niño are:

　　Rise in surface pressure over the Indian Ocean, Indonesia, and Australia

　　Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean

　　Trade winds in the south Pacific weaken or head east

　　Warm air rises near Peru, causing rain in the northern Peruvian deserts

　　Warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific.

　　El Niño's warm rush of nutrient-poor water heated by its eastward passage in the Equatorial Current, replaces the cold, nutrient-rich surface water of the Humboldt Current. When El Niño conditions last for many months, extensive ocean warming and the reduction in easterly trade winds limits upwelling of cold nutrient-rich deep water, and its economic impact to local fishing for an international market can be serious.

　　Effects of El Niño

　　El Niño conditions influence wintertime atmospheric flow across the eastern North Pacific and North America. There is considerable event-to-event variability in the character of El Niño episodes and in some areas, impacts can vary substantially from one event to another. However, there are some sections of the United States where impacts are fairly consistent and predictable, especially when associated with strong El Niño episodes. In general, El Niño results in increased precipitation across California and the southern tier of states, and decreased precipitation in the Pacific Northwest and in the Ohio and Tennessee Valleys. A milder than normal winter across the northern states and western Canada is also a common effect. In the eastern United States, El Niño episodes favor more coastal storms at the expense of Alberta Clippers (fast eastward-tracking storms across the northern states) in winter and early spring. During the warm season, El Niño influences hurricane development, resulting in more eastern Pacific hurricanes and fewer Atlantic hurricanes.

　　Cultural history and prehistoric information

　　An early recorded mention of the term "El Niño" to refer to climate occurred in 1892, when Captain Camilo Carrillo told the geographical society congress in Lima that Peruvian sailors named the warm northerly current "El Niño" because it was most noticeable around Christmas. The phenomenon had long been of interest because of its effects on the guano industry and other enterprises that depend on biological productivity of the sea.

　　Charles Todd, in 1893, suggested droughts in India and Australia tended to occur at the same time; Norman Lockyer noted the same in 1904. An El Niño connection with flooding was reported in 1895 by Pezet and Eguiguren. In 1924, Gilbert Walker (for whom the Walker circulation is named) coined the term "Southern Oscillation".

　　The major 1982–83 El Niño led to an upsurge of interest from the scientific community. The period 1990–1994 was unusual in that El Niños have rarely occurred in such rapid succession. An especially intense El Niño event in 1998 caused an estimated 16% of the world's reef systems to die. The event temporarily warmed air temperature by 1.5°C, compared to the usual increase of 0.25°C associated with El Niño events. Since then, mass coral bleaching has become common worldwide, with all regions having suffered "severe bleaching".

　　Major ENSO events were recorded in the years 1790–93, 1828, 1876–78, 1891, 1925–26, 1972–73, 1982–83, 1997–98 and 2009–2010, with 1997-1998 being one of the strongest ever.