初一英语美文背诵
初一英语美文背诵
在英语教学中,开展经典美文教学不仅能提高学生的文学水平,而且能提高学生的英语素养,对培养学生的语言素养和人文素养具有极大益处,更能丰富学生的精神世界,磨炼学生的意志。学习啦小编整理了初一英语美文，欢迎阅读!
初一英语美文篇一
学习啦在线学习网 The Microscopic Technique
Each advance in microscopic technique has provided scientists with new perspectives on thefunction of living organisms and the nature of matter itself. The invention of the visible lightmicroscope late in the sixteenth century introduced a previously unknown realm of singlecelled plants and animals.In the twentieth century, electron microscopes have provided directviews of viruses and minuscule surface structures. Now another type of microscope, one thatutilizes x rays rather than light or electrons, offers a different way of examining tiny details; itshould extend human perception still farther into the natural world.
The dream of building an x ray microscope dates to back 1895; its development, however wasvirtually halted in the 1940's because the development of the electron microscope wasprogressing rapidly. During the 1940's, electron microscopes routinely achieved resolutionbetter than that poss ible with a visible light microscope, while the performance of x raymicroscopes resisted improvement. In recent years,however, interest in x ray microscopes hasrevived,largely because of advances such as thedevelopment of new sources of x rayillumination. As a result, the brightness available today is millions of times tha t of x raytubes, which, for most of the century, were the only available sources of soft x rays.The new xray microscopes considerably improve on the resolution provided by optical microscopes. Theycan also be used to map the distribution of certain chemical elements. Some can form picturesin extremely short times; others hold the promise of special capabilities such as threedimensional imaging. Unlike conventional electron microscope, x ray microscope enablesspecimens to be kept in air and in water, which means that biological samples can be studiedunder conditions similar to their natural state. The illumination used, so called soft x rays inthe wavelength range of twenty to forty angstroms (an angstrom is one ten billionth of ameter), is also sufficiently penetrating to image intact biological cells in ma ny cases.
Because of the wavelength of the x rays used,soft x ray microscopes will never match thehighest resolution possible with electron microscopes.
Rather, their special properties will make possible investigations that will complement thoseperformed with light and electron based instruments.
显微技术
学习啦在线学习网 显微镜技术的每一个进步都给科学家提供了看待生物体的功能和其性质的新观察方式。 16 世纪晚期可视光显微镜的发明引入了一个以前一无所知的单细胞植物和动物的领域。 20 世纪电子显微镜提供了对病毒和极微物体的表面结构的直接观察。 现在一种新的显微镜，利用X 光而不是自然可见光或电子，为观察微小细节提供了不同的观察方式，它将扩展人类对自然世界进行的更深入的认识。 研制X 光显微镜的梦想可追溯到 1875 年;但它的发展却在 20 世纪 40 年代实际上停止了，因为电子显微镜的发展进行很快。 在 40年代，电子显微镜毫无例外地比可见光显微镜获得了更好的分辨能力。 然而X 光显微镜的表现却没有改进。 但近年来，对它的兴趣又复活了，这很大程度是因为例如X 射线在新光源上的发展的结果。 结果，今天可得到的亮度是大半个世纪以来唯一可得到的X 光源-X 光管的几百万倍。 新的 X 光显微镜相当大地提高了电子学显微镜提供的分辨能力。 它们也可用来给某些化学元素绘制分布图。 某些 X 光显微镜可以在极短的时间里成像。 另一些可望具备三维成像的特殊功能。 与传统的电子显微镜成像术不同，X 光显微镜成像术可使分析样本保留在空气或水中。 这就意味着生物样品可以在与它们自然环境相近的条件下被观察研究。 其使用的照明度，即所谓的软性X射线，其波长在20 到40 埃之间(1 米的 100亿分之一为 1 埃)。 在许多情况下也能够穿透完整无缺的生物细胞并成像。 由于使用的X射线的波长使软性X 射线显微镜永远比不上电子显微镜可能具有的最高分辨力。 不过他们特殊的功能将可能补充那些用自然光和电子仪器所进行的观察。
初一英语美文篇二
The Language of Music
A painter hangs his or her finished pictures on a wall, and everyone can see it. A composerwrites a work, but no one can hear it until it is performed. Professional singers and players havegreat responsibilities, for the composer is utterly dependent on them. A student of musicneeds as long and as arduous a training to become a performer as a medical student needs tobecome a doctor. Most training is concerned with technique, for musicians have to have themuscular proficiency of an athlete or a ballet dancer. Singers practice breathing every day,as their vocal chords would be inadequate without controlled muscular support. Stringplayers practice moving the fingers of the left hand up and down, while drawing the bow to andfro with the right arm—two entirely different movements.
Singers and instruments have to be able to get every note perfectly in tune. Pianists are sparedthis particular anxiety, for the notes are already there, waiting for them, and it is the pianotuner’s responsibility to tune the instrument for them. But they have their own difficulties; thehammers that hit the string have to be coaxed not to sound like percussion, and eachoverlapping tone has to sound clear.
This problem of getting clear texture is one that confronts student conductors: they have tolearn to know every note of the music and how it should sound, and they have to aim atcontrolling these sound with fanatical but selfless authority.
学习啦在线学习网 Technique is of no use unless it is combined with musical knowledge and understanding. Greatartists are those who are so thoroughly at home in the language of music that they can enjoyperforming works written in any century.
音乐的语言
画家将已完成的作品挂在墙上，每个人都可以观赏到。 作曲家写完了一部作品，得由演奏者将其演奏出来，其他人才能得以欣赏。因为作曲家是如此完全地依赖于职业歌手和职业演奏者，所以职业歌手和职业演奏者肩上的担子可谓不轻。 一名学音乐的学生要想成为一名演奏者，需要经受长期的、严格的训练，就象一名医科的学生要成为一名医生一样。 绝大多数的训练是技巧性的。 音乐家们控制肌肉的熟练程度，必须达到与运动员或巴蕾舞演员相当的水平。 歌手们每天都练习吊嗓子，因为如果不能有效地控制肌肉的话，他们的声带将不能满足演唱的要求。 弦乐器的演奏者练习的则是在左手的手指上下滑动的同时，用右手前后拉动琴弓--两个截然不同的动作。歌手和乐器演奏者必须使所有的音符完全相同协调。 钢琴家们则不用操这份心，因为每个音符都已在那里等待着他们了。 给钢琴调音是调音师的职责。 但调音师们也有他们的难处： 他们必须耐心地调理敲击琴弦的音锤，不能让音锤发出的声音象是打击乐器，而且每个交叠的音都必须要清晰。如何得到乐章清晰的纹理是学生指挥们所面临的难题：他们必须学会了解音乐中的每一个音及其发音之道。 他们还必须致力于以热忱而又客观的权威去控制这些音符。除非是和音乐方面的知识和悟性结合起来，单纯的技巧没有任何用处。 艺术家之所以伟大在于他们对音乐语言驾轻就熟，以致于可以满怀喜悦地演出写于任何时代的作品。
初一英语美文篇三
学习啦在线学习网 The History of Chemistry
Chemistry did not emerge as a science until after the scientific revolution in the seventeenthcentury and then only rather slowly and laboriously. But chemical knowdedge is as old ashistory, being almost entirely concerned with the practical arts of living. Cooking is essentiallya chemical process; so is the melting of metals and the administration of drugs and poisons.This basic chemical knowledge, which was applied in most cases as a rule of thumb, wasnevertheless dependent on previous experiment. It also served to stimulate a fundamentalcuriosity about the processes themselves. New information was always being gained asartisans improved techniques to gain better results. The development of a scientific approachto chemistry was, however, hampered by several factors. The most serious problem was thevast range of material available and the consequent difficulty of organizing it into somesystem. In addition, there were social and intellectual difficulites, chemistry is nothing if notpractical; those who practice it must use their hands, they must have a certain practical flair.Yet in many ancient civilizations, practical tasks were primarily the province of a slavepopulation. The thinker or philosopher stood apart from this mundane world, where thepractical arts appeared to lack any intellectual content or interest. The final problem for earlychemical science was the element of secrecy. Experts in specific trades had developed theirown techniques and guarded their knowledge to prevent others from stealing their livelihood.Another factor that contributed to secrecy was the esoteric nature of the knowledge of aalchemists, who were trying to transform base metals into gold or were concerned with thehunt for the elixir that would bestow the blessing of eternal life. In one sense, the second ofthese was the more serious impediment because the records of the chemical processes thatearly alchemists had discovered were often written down in symbolic language intelligible tovery few or in symbols that were purposely obscure.
化学的历史
化学在17 世纪的科技革命后才成为一门科学，其发展是缓慢而艰难的。 但化学知识却象人类历史一样古老，与人们实际生活密切相关。 做饭基本上是一个化学过程。 同样，金属熔炼、使用药品或毒剂也是如此。 人们在大多数情况下只是粗糙地运用这些基本化学知识，但这些基本知识的确是来自于前人的实验。 它们同时也激发了人们对化学本身的兴趣。 匠人们利用新技术来改良工艺，就增加了对化学的了解。 但是，化学科学方法的发展却有许多阻碍的因素。 其中最严重的问题就是要把浩如烟海的物质归纳为若干系统确实很困难。 此外，还有社会和知识的原因。 离开实际用途，化学就毫无价值;研究化学的人必须亲自动手，这就要求他们要有很强的动手能力。但在许多古代文明中，动手的活都是奴隶的行当。 思想家与哲学家与此劳碌决不沾边，因为在他们看来，实际操作技能低智而乏味。 最后，还有一个原因妨碍早期化学的发展，那就是保密。 某个行家一旦发现了新技术，就竭力保密以防被人偷了饭碗。 另一个原因加剧了知识封锁这是因为炼金术士的知识的神秘性。这些术士们要么想他便宜的金属变成黄金，要么期望找到一种长生不老药。从某种意义上说，这第二个因素带来了更严重的阻碍，因为早期术士们的研究成果记载于鲜为人知的或故意让人不懂的符号中。
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