他们没有农业，但是经过几千年，已经发展了探索自身环境的技术和设备。他们是基于大量出现鲑鱼、大比目鱼和其他多种鱼类的自身流域和水岸捕鱼的经济;基于从落基山水岸聚集了鲍鱼、蚌类、蛤和其他贝壳动物的经济;基于捕猎地域和海洋哺乳动物的经济;以及基于收集野生植物的食物的经济;
27.The musicians within the orchestra’s ranks enrich their communityimmeasurably by ensuring that new generations of musicians, or simplymusic lovers, are given the kind of superior instruction that only anactively engaged, practicing musician can impart.
有管弦乐家的级别音乐家们可以无限制地有利于他们的团体，靠通过确保给新一代的音乐家们或简易的音乐爱好者们一种高级的指导，这种指导只能由一个活的已加入的具有实践经验的音乐家能传授。
28.Since Canadian metropolitan areas have only one-quarter the numberof kilometers of superhighways per capita as United States metropolitanareas – and at least as much resistance to constructing more –suburbanization of peoples and functions is less extensive north of theborder than south.
因为加拿大地大都市区域每城市高速公路公里总数量只有美国的四分之一，而且至少根据相当的居民数量去建设更多的高速公路，比较南部边界的而言，人群和设施的都市化在北部边界区延伸度较少。
29.They made available kinds of popular music heard previously onlylimited geographical areas or by specific ethnic and social groups –especially the blues, gospel songs, and jazz of African Americans andthe traditional music of the southern Appalachian Mountains and otherrural areas of the southern and western United States.
他们制造了相当多种类的流行音乐，这些音乐以前只限于在地理区域或特殊的种族和社会群体能被听到，尤其是象布噜斯、福音歌曲和非洲美国人的爵士乐和阿巴拉奇亚山脉南部和其他美国南部和西部的乡村区域传统音乐。
30.The development of the railroad and telegraph systems during themiddle third of the nineteenth century led to significant improvementsin the speed, volume, and regularity of shipments and communications,making possible a fundamental transformation in the production anddistribution of goods.
在第三个十九世纪中期铁路和电报系统的发展导致了在速度、音量和普通的船运和通讯上的明显的进步，使生产和分发货物方面的一个基础的转变有可能发生。
31.Add to this the timidity with which unschooled artisans –originally trained as stonemasons, carpenters, or cabinetmakers –attacked the medium from which they were to make their images, and oneunderstands more fully the development of sculpture made in the UnitedStates in the late eighteenth century.
由于未受学校教育的艺术家们的胆却，他们通常被训练成石匠、木匠或家具师， 抨击了在媒体中他们以前造就的自我形象和一个理解，这个理解就是雕塑的发展在十八世纪晚期的美国更加完全的发生了。
32.Instead of trying to keep down the body temperature deep inside thebody, which would involved the expenditure of water and energy, desertmammals allow their temperatures to rise to what would normally befever height, and temperatures as high as 46 degrees Celsius have beenmeasured in Grant’s gazelles.
除了尽量去保持身体深处的低体温，这将包括支出水和能量，沙漠哺乳动物们允许他们的温度上升到一个通常来说是发烧的温度并且温度高达46摄氏度，这已被在格兰特瞪羚测得。
33.Solitary roosters shelter in dense vegetation or enter a cavity –horned larks dig holes in the ground and ptarmigan burrow into snowbanks – but the effect of sheltering is magnified by several birdshuddling together in the roots, as wrens, swifts, brown creepers,bluebirds, and anis do.
孤独的雄鸡躲避在茂盛的植被下或进入洞穴躲藏，如角状的百灵在地面挖洞躲藏和松鸡在雪岸挖洞躲藏，但是象鹪鹩、雨燕、褐色的爬行动物、蓝知更鸟和anis所做的一样，由于多只鸟一起拥挤在根茎下，所以躲避的效果被扩大。
34.Each SMSA would contain at least (a) one central city with 50000inhabitants or more or (b) two cities having shared boundaries andconstituting, for general economic and social purposes, a singlecommunity with a combined population of at least 50000, the smaller ofwhich must have a population of at least 15000.
每个大城市及其郊区至少能容纳(a)一个5000居民人口的中心城市或(b)为了一个普通的经济和社会目的共享边界和律法的两个城市，一个单个的融合的社区人口至少50000，更小一点的社区必须有至少15000人口。
35.The growing custom of regularly assembling from afar therepresentatives of all kinds of groups, not only for politicalconventions, but also for commercial, professional, learned, andvocational ones… in turn supported the multiplying hotels.
增长中的风俗，通常集合了所有种类的群体从远方来的代表，不仅为政治惯例还是为贸易上、专业上、已学习的和职业的惯例…，轮流支持了增长中的宾馆。
36.Two species of these finches, named for the way the upper and lowerparts of their bills cross, rather than meet in the middle, reside inthe evergreen forests of North American and feed on the seeds heldwithin the cones of coniferous trees.
以他们上部和较低部分的嘴的交叉命名，而不是中间部分相遇的部分命名，这两种雀类居住在北美四季常青的森林里并且以包含在锥状的松果树球内的种子为食。
37.The beginning of a major change was foreshadowed in the later1860’s, when the union Pacific Railroad at last began to build westwardfrom the Central Plains city of Omaha to meet the Central PacificRailroad advancing eastward from California through the formidablebarrier of the Sierra Nevada.
主要变化的开端在18世纪60年代晚期被预示了，当时在太平洋铁路联合体最后开始建设从Omaha的城市中心平原到连接太平洋铁路中心向西的铁路，它推进了从加利福尼亚穿过Sierra Nevada的重重险阻向东的铁路
38.The argument that humans, even in prehistoric, had some numbersense, at least to the extent of recognizing the concept of more andless when some objects were added to or taken away from a small group,seems fair, for studies have shown that some animal possess such asense.
关于人类即使是史前人类都具有一些数字的感觉的争论，当或多或少一些对象被从一个小团体内加入或拿走的概念，最后导致这个概念的认可，这看起来是公平的，因为研究表明一些动物拥也有这样的感觉。
39.A useful definition of an air pollutant is a compound added directlyor indirectly by humans to the atmosphere in such quantities as toaffect humans, animals, vegetation, or materials adversely.
一个有用的定义关于空气污染是被人类直接加入或间接加入到大气中，那些空气质量反面地影响人类、动物、植被或原材料的空气的混合体。
40.The tight arrangement enabled the Mandans to protect themselves moreeasily from the attacks of others who might seek to obtain some of thefood these highly capable farmers stored from one year tonext.
紧凑的安排使曼旦人能更容易地，从那些寻找获得那些高产的农民们年复一年地存储的一些食物的其他族人的袭击中，保护他们自己。
41.Noother set of colonists took so seriously one expression of the period,“Leisure is time for doing something useful,” in the countrysidefarmers therefore relieved the burden of the daily routine with suchdouble-purpose relaxations as hunting, fishing, andtrapping.
没有其他的殖民者在那个时期如此严肃的持有一个的申明：休闲对做事有利，乡下农民们理所当然的收到如此双重任务：日常事务的重担和狩猎、捕鱼和诱捕的闲暇。
42.Life on Earth has continually been in flux as slowphysical and chemical changes have occurred on Earth, but life needstime to adapt – time for migration and genetic adaptation withinexisting species and time for the proliferation of new genetic materialand new species that may be able to survive inenvironments.
地球上的生命不断地演化，就象存在于地球中的缓慢地物理的和化学的变化，但是生物需要时间去适应，这就是现存物种的迁移和基因改变的时间，和以便能在环境中生存的新基因材料和新物种的繁殖的时间。
43.Some fossil bones have all theinterstitial spaces filled with foreign minerals, including the marrowcavity, if there is one, while others have taken up but little fromtheirsurroundings.
一些石化的骨头的所有裂缝的空隙，包括骨髓空腔，都充满了外来的矿石，如果这儿还有有一个空腔当其他的空腔都已被占据，填充物很少是来源于他们的环境。
44.By 1776 the fine art of painting as it had developed inwestern Europe up to this time had been introduced into the Americancolonies through books and paints, European visitors and immigrants,and traveling colonists who brought back copies (and a few originals)of old master paintings and acquaintance with European artinstitutions.
杰出的绘画艺术，在西欧发展，直到现在通过书、绘画、欧洲访问者和移民被介绍给美洲殖民者和游移不定的殖民者，他们买回旧的大师的绘画和欧洲艺术机构熟识的的复制品(很少有原件)。
45.The terminology by which artists weredescribed at the time suggests their status: “limner” was usuallyapplied to the anonymous portrait painter up to the 1760’s: “painter”characterized anyone who could paint a flatsurface.
艺术家们当时描述的术语表明了他们的状态，如“画匠”一词通常应用在匿名的肖像画家;直到十七世纪60年代，“油漆匠”刻画了那些能在平的表面刷漆的人。
46.A few art collectors James Bowdoin III of Boston, WilliamByrd of Virginia, and the Aliens and Hamiltons of Philadelphiaintroduced European art traditions to those colonists privileged tovisit their galleries, especially aspiring artists, and established intheir respective communities the idea of the value of art and the needfor institutions devoted to its encouragement.
一些艺术收藏家，如波士顿的JamesBowdoin III、弗吉尼亚的William Byrd和凤凰城的Aliens andHamiltons家族，介绍欧洲的艺术给那些有特权去参观他们画廊，尤其是那些有抱负的艺术家们的画廊的殖民者，并且建立了基于他们各自团体的艺术价值的观点和基于投入了他们资金的艺术机构的需求。
47.The achievements of the colonial artists,particularly those of Copley, West, and Peale, lent credence to theboast that the new nation was capable of encouraging genius and thatpolitical liberty was congenial to the development of taste – anecessary step before art could assume an important role in the newrepublic.
殖民艺术家们的成果，尤其是那些肖像画家、西部的和画家，信任值得夸耀的事，如新的国家有能力鼓励天才艺术家和政治自由有相似的发展的口味，这是艺术能在新的公众面前扮演一个重要的角色前的一个必要的一步。
48.In its grand and impressiveterminals and stations, architects recreated historic Roman temples andpublic baths, French chateaus and Italian bell towers – edifices thatpeople used as stages for many of everyday life’s high emotions:meeting and parting, waiting and worrying, planning new starts orcominghome.
除了豪华的和给人印象深刻的月台和站点，建筑师们重新创建了著名的罗马庙宇和公共浴场以及法式城堡和意大利钟塔，这些建筑被人们用来作为提高人们日常生活的情趣的场所如：会见和道别朋友、等待和担忧、计划新的行程和回家。
49.Moreover, in addition to itsbeing a transportation pathway equipped with a mammoth physical plantof tracks signals, crossings, bridges, and junctions, plus telegraphand telephone lines the railroad nurtured factory complexes, coatpiles, warehouses, and generating stations, forming along itsright-of-way what has aptly been called “the metropolitan corridor” ofthe American landscape.
更多的是，除了它成为交通线路要配备一个庞大的物理设备用来跟踪信号、交叉、桥梁和加上电报和电话线的连接，铁路滋养了工厂的联合体、XX表面、仓库和生产站，塑造着可通行的适当的被叫作大都市走廊的美洲风景。
50.It was in the cities that the elements that can be associatedwith modern capitalism first appeared – the use of money and commercialpaper in place of barter, open competition in place of social deferenceand hierarchy, with an attendant rise in social disorder, and theappearance of factories using coal or water power in place ofindependent craftspeople working with handtools.
城市中，和现代资本主义关联的因素首先出现，他们是钱和贸易纸币的使用代替物物交换、伴随着一个社会混乱的上升，开放的竞争代替社会顺从和阶级、使用煤和水能源的工厂出现代替独立的手工艺人的手工工作。
