初一英語美文背誦
初一英語美文背誦
在英語教學中,開展經(jīng)典美文教學不僅能提高學生的文學水平,而且能提高學生的英語素養(yǎng),對培養(yǎng)學生的語言素養(yǎng)和人文素養(yǎng)具有極大益處,更能豐富學生的精神世界,磨煉學生的意志。學習啦小編整理了初一英語美文，歡迎閱讀!
初一英語美文篇一
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.
顯微技術
顯微鏡技術的每一個進步都給科學家提供了看待生物體的功能和其性質(zhì)的新觀察方式。 16 世紀晚期可視光顯微鏡的發(fā)明引入了一個以前一無所知的單細胞植物和動物的領域。 20 世紀電子顯微鏡提供了對病毒和極微物體的表面結(jié)構的直接觀察。 現(xiàn)在一種新的顯微鏡，利用X 光而不是自然可見光或電子，為觀察微小細節(jié)提供了不同的觀察方式，它將擴展人類對自然世界進行的更深入的認識。 研制X 光顯微鏡的夢想可追溯到 1875 年;但它的發(fā)展卻在 20 世紀 40 年代實際上停止了，因為電子顯微鏡的發(fā)展進行很快。 在 40年代，電子顯微鏡毫無例外地比可見光顯微鏡獲得了更好的分辨能力。 然而X 光顯微鏡的表現(xiàn)卻沒有改進。 但近年來，對它的興趣又復活了，這很大程度是因為例如X 射線在新光源上的發(fā)展的結(jié)果。 結(jié)果，今天可得到的亮度是大半個世紀以來唯一可得到的X 光源-X 光管的幾百萬倍。 新的 X 光顯微鏡相當大地提高了電子學顯微鏡提供的分辨能力。 它們也可用來給某些化學元素繪制分布圖。 某些 X 光顯微鏡可以在極短的時間里成像。 另一些可望具備三維成像的特殊功能。 與傳統(tǒng)的電子顯微鏡成像術不同，X 光顯微鏡成像術可使分析樣本保留在空氣或水中。 這就意味著生物樣品可以在與它們自然環(huán)境相近的條件下被觀察研究。 其使用的照明度，即所謂的軟性X射線，其波長在20 到40 埃之間(1 米的 100億分之一為 1 埃)。 在許多情況下也能夠穿透完整無缺的生物細胞并成像。 由于使用的X射線的波長使軟性X 射線顯微鏡永遠比不上電子顯微鏡可能具有的最高分辨力。 不過他們特殊的功能將可能補充那些用自然光和電子儀器所進行的觀察。
初一英語美文篇二
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.
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.
音樂的語言
畫家將已完成的作品掛在墻上，每個人都可以觀賞到。 作曲家寫完了一部作品，得由演奏者將其演奏出來，其他人才能得以欣賞。因為作曲家是如此完全地依賴于職業(yè)歌手和職業(yè)演奏者，所以職業(yè)歌手和職業(yè)演奏者肩上的擔子可謂不輕。 一名學音樂的學生要想成為一名演奏者，需要經(jīng)受長期的、嚴格的訓練，就象一名醫(yī)科的學生要成為一名醫(yī)生一樣。 絕大多數(shù)的訓練是技巧性的。 音樂家們控制肌肉的熟練程度，必須達到與運動員或巴蕾舞演員相當?shù)乃健?歌手們每天都練習吊嗓子，因為如果不能有效地控制肌肉的話，他們的聲帶將不能滿足演唱的要求。 弦樂器的演奏者練習的則是在左手的手指上下滑動的同時，用右手前后拉動琴弓--兩個截然不同的動作。歌手和樂器演奏者必須使所有的音符完全相同協(xié)調(diào)。 鋼琴家們則不用操這份心，因為每個音符都已在那里等待著他們了。 給鋼琴調(diào)音是調(diào)音師的職責。 但調(diào)音師們也有他們的難處： 他們必須耐心地調(diào)理敲擊琴弦的音錘，不能讓音錘發(fā)出的聲音象是打擊樂器，而且每個交疊的音都必須要清晰。如何得到樂章清晰的紋理是學生指揮們所面臨的難題：他們必須學會了解音樂中的每一個音及其發(fā)音之道。 他們還必須致力于以熱忱而又客觀的權威去控制這些音符。除非是和音樂方面的知識和悟性結(jié)合起來，單純的技巧沒有任何用處。 藝術家之所以偉大在于他們對音樂語言駕輕就熟，以致于可以滿懷喜悅地演出寫于任何時代的作品。
初一英語美文篇三
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.
化學的歷史
化學在17 世紀的科技革命后才成為一門科學，其發(fā)展是緩慢而艱難的。 但化學知識卻象人類歷史一樣古老，與人們實際生活密切相關。 做飯基本上是一個化學過程。 同樣，金屬熔煉、使用藥品或毒劑也是如此。 人們在大多數(shù)情況下只是粗糙地運用這些基本化學知識，但這些基本知識的確是來自于前人的實驗。 它們同時也激發(fā)了人們對化學本身的興趣。 匠人們利用新技術來改良工藝，就增加了對化學的了解。 但是，化學科學方法的發(fā)展卻有許多阻礙的因素。 其中最嚴重的問題就是要把浩如煙海的物質(zhì)歸納為若干系統(tǒng)確實很困難。 此外，還有社會和知識的原因。 離開實際用途，化學就毫無價值;研究化學的人必須親自動手，這就要求他們要有很強的動手能力。但在許多古代文明中，動手的活都是奴隸的行當。 思想家與哲學家與此勞碌決不沾邊，因為在他們看來，實際操作技能低智而乏味。 最后，還有一個原因妨礙早期化學的發(fā)展，那就是保密。 某個行家一旦發(fā)現(xiàn)了新技術，就竭力保密以防被人偷了飯碗。 另一個原因加劇了知識封鎖這是因為煉金術士的知識的神秘性。這些術士們要么想他便宜的金屬變成黃金，要么期望找到一種長生不老藥。從某種意義上說，這第二個因素帶來了更嚴重的阻礙，因為早期術士們的研究成果記載于鮮為人知的或故意讓人不懂的符號中。
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