俞敏洪說：背完這100個句子，你已經(jīng)背過7000個單詞！
1. Typical of the grassland dwellers of the continent is the American antelope, or pronghorn.
1.美洲羚羊，或稱叉角羚，是該大陸典型的草原動物。
2. Of the millions who saw Haley’s comet in 1986, how many people will live long enough to see it return in the twenty-first century.
2. 1986年看見哈雷慧星的千百萬人當中，有多少人能夠長壽到足以目睹它在二十一世紀的回歸呢？
3. Anthropologists have discovered that fear, happiness, sadness, and surprise are universally reflected in facial expressions.
3.人類學(xué)家們已經(jīng)發(fā)現(xiàn)，恐懼，快樂，悲傷和驚奇都會行之于色，這在全人類是共通的。
4. Because of its irritating effect on humans, the use of phenol as a general antiseptic has been largely discontinued.
4.由于苯酚對人體帶有刺激性作用，它基本上已不再被當作常用的防腐劑了。
5. In group to remain in existence, a profit-making organization must, in the long run, produce something consumers consider useful or desirable.
5.任何盈利組織若要生存，最終都必須生產(chǎn)出消費者可用或需要的產(chǎn)品。
6. The greater the population there is in a locality, the greater the need there is for water, transportation, and disposal of refuse.
6.一個地方的人口越多，其對水，交通和垃圾處理的需求就會越大。
7. It is more difficult to write simply, directly, and effectively than to employ flowery but vague expressions that only obscure one’s meaning.
7.簡明，直接，有力的寫作難于花哨，含混而意義模糊的表達。
8. With modern offices becoming more mechanized, designers are attempting to personalize them with warmer, less severe interiors.
8.隨著現(xiàn)代辦公室的日益自動化，設(shè)計師們正試圖利用較為溫暖而不太嚴肅的內(nèi)部裝飾來使其具有親切感。
9. The difference between libel and slander is that libel is printed while slander is spoken.
9.誹謗和流言的區(qū)別在于前者是書面的，而后者是口頭的。
10. The knee is the joints where the thigh bone meets the large bone of the lower leg.
10.膝蓋是大腿骨和小腿脛的連接處。
11. Acids are chemical compounds that, in water solution, have a sharp taste, a corrosive action on metals, and the ability to turn certain blue vegetable dyes red.
11.酸是一種化合物，它在溶于水時具有強烈的氣味和對金屬的腐蝕性，并且能夠使某些藍色植物染料變紅。
12. Billie Holiday’s reputation as a great jazz-blues singer rests on her ability to give emotional depth to her songs.
12. Billie Holiday’s作為一個爵士布魯斯樂杰出歌手的名聲建立在能夠賦予歌曲感情深度的能力。
13. Essentially, a theory is an abstract, symbolic representation of what is conceived to be reality.
13.理論在本質(zhì)上是對認識了的現(xiàn)實的一種抽象和符號化的表達。
14. Long before children are able to speak or understand a language, they communicate through facial expressions and by making noises.
14.兒童在能說或能聽懂語言之前，很久就會通過面部表情和靠發(fā)出噪聲來與人交流了。
15. Thanks to modern irrigation, crops now grow abundantly in areas where once nothing but cacti and sagebrush could live.
15.受當代灌溉(技術(shù)設(shè)施)之賜，農(nóng)作物在原來只有仙人掌和蕎屬科植物才能生存的地方旺盛的生長。
16. The development of mechanical timepieces spurred the search for more accurate sundials with which to regulate them.
16.機械計時器的發(fā)展促使人們尋求更精確的日晷，以便校準機械計時器。
17. Anthropology is a science in that anthropologists use a rigorous set of methods and techniques to document observations that can be checked by others.
17.人類學(xué)是一門科學(xué)，因為人類學(xué)家采用一整套強有力的方法和技術(shù)來記錄觀測結(jié)果，而這樣記錄下來的觀測結(jié)果是供他人核查的。
18. Fungi are important in the process of decay, which returns ingredients to the soil, enhances soil fertility, and decomposes animal debris.
18.真菌在腐化過程中十分重要，而腐化過程將化學(xué)物質(zhì)回饋于土壤，提高其肥力，并分解動物糞便。
19. When it is struck, a tuning fork produces an almost pure tone, retaining its pitch over a long period of time.
19.音叉被敲擊時，產(chǎn)生幾乎純質(zhì)的音調(diào)，其音量經(jīng)久不衰。
20. Although pecans are most plentiful in the southeastern part of the United States, they are found as far north as Ohio and Illinois.
20.雖然美洲山河桃樹最集中于美國的東南部但是在北至俄亥俄州及伊利諾州也能看見它們。
21. Eliminating problems by transferring the blame to others is often called scape-goating.
21.用怪罪別人的辦法來解決問題通常被稱為尋找替罪羊。
22. The chief foods eaten in any country depend largely on what grows best in its climate and soil.
22.一個國家的主要食物是什么，大體取決于什么作物在其天氣和土壤條件下生長得最好。
23. Over a very large number of trials, the probability of an event’s occurring is equal to the probability that it will not occur.
23.在大量的實驗中，某一事件發(fā)生的幾率等于它不發(fā)生的幾率。
24. Most substance contract when they freeze so that the density of a substance’s solid is higher than the density of its liquid.
24.大多數(shù)物質(zhì)遇冷收縮，所以他們的密度在固態(tài)時高于液態(tài)。
25. The mechanism by which brain cells store memories is not clearly understood.
25.大腦細胞儲存記憶的機理并不為人明白。
26. By the middle of the twentieth century, painters and sculptors in the United States had begun to exert a great worldwide influence over art.
26.到了二十一世紀中葉，美國畫家和雕塑家開始在世界范圍內(nèi)對藝術(shù)產(chǎn)生重大影響。
27. In the eastern part of New Jersey lies the city of Elizabeth, a major shipping and manufacturing center.
27.伊麗莎白市，一個重要的航運和制造業(yè)中心，坐落于新澤西州的東部。
28. Elizabeth Blackwell, the first woman medical doctor in the United States, founded the New York Infirmary, an institution that has always had a completely female medical staff.
28. Elizabeth Blackwell，美國第一個女醫(yī)生，創(chuàng)建了員工一直為女性紐約診所。
29. Alexander Graham Bell once told his family that he would rather be remembered as a teacher of the deaf than as the inventor of the telephone.
29. Alexander Graham Bell曾告訴家人，他更愿意讓后人記住他是聾子的老師，而非電話的發(fā)明者。
30. Because its leaves remain green long after being picked, rosemary became associated with the idea of remembrance.
30.采摘下的迷迭香樹葉常綠不衰，因此人們把迷迭香樹與懷念聯(lián)系在一起。
31. Although apparently rigid, bones exhibit a degree of elasticity that enables the skeleton to withstand considerable impact.
31.骨頭看起來是脆硬的，但它也有一定的彈性，使得骨骼能夠承受相當?shù)拇驌簟?
32. That xenon could not FORM chemical compounds was once believed by scientists.
32.科學(xué)家曾相信：氙氣是不能形成化合物的。
33. Research into the dynamics of storms is directed toward improving the ability to predict these events and thus to minimize damage and avoid loss of life. 　 33.對風(fēng)暴動力學(xué)的研究是為了提高風(fēng)暴預(yù)測從而減少損失，避免人員傷亡。
34. The elimination of inflation would ensure that the amount of money used in repaying a loan would have the same value as the amount of money borrowed. 34.消除通貨膨脹應(yīng)確保還貸的錢應(yīng)與所貸款的價值相同。
35. Futurism, an early twentieth-century movement in art, rejected all traditions and attempted to glorify contemporary life by emphasizing the machine and motion.
35.未來主義，二十世紀早期的一個藝術(shù)思潮。拒絕一切傳統(tǒng)，試圖通過強調(diào)機械和動態(tài)來美化生活。
36. One of the wildest and most inaccessible parts of the United States is the Everglades where wildlife is abundant and largely protected.
36. Everglades是美國境內(nèi)最為荒涼和人跡罕至的地區(qū)之一，此處有大量的野生動植物而且大多受(法律)保護。
37. Lucretia Mott’s influence was so significant that she has been credited by some authorities as the originator of feminism in the United States.
37. Lucretia Mott’s的影響巨大，所以一些權(quán)威部門認定她為美國女權(quán)運動的創(chuàng)始人。
38. The activities of the international marketing researcher are frequently much broader than those of the domestic marketer.
38.國際市場研究者的活動范圍常常較國內(nèi)市場研究者廣闊。
39. The continental divide refers to an imaginary line in the North American Rockies that divides the waters flowing into the Atlantic Ocean from those flowing into the Pacific.
39.大陸分水嶺是指北美洛磯山脈上的一道想象線，該線把大西洋流域和太平洋流域區(qū)分開來。
40. Studies of the gravity field of the Earth indicate that its crust and mantle yield when unusual weight is placed on them.
40.對地球引力的研究表明，在不尋常的負荷之下地殼和地幔會發(fā)生位移。
41. The annual worth of Utah’s manufacturing is greater than that of its mining and farming combined.
41.尤它州制造業(yè)的年產(chǎn)值大于其工業(yè)和農(nóng)業(yè)的總和。
42. The wallflower is so called because its weak stems often grow on walls and along stony cliffs for support.
42.墻花之所以叫墻花，是因為其脆弱的枝干經(jīng)常要靠墻壁或順石崖生長，以便有所依附。
43. It is the interaction between people, rather than the events that occur in their lives, that is the main focus of social psychology.
43.社會心理學(xué)的主要焦點是人與人之間的交往，而不是他們各自生活中的事件。
44. No social crusade aroused Elizabeth Williams’ enthusiasm more than the expansion of educational facilities for immigrants to the United States.
44.給美國的新移民增加教育設(shè)施比任何社會運動都更多的激發(fā)了Elizabeth Williams的熱情。
45. Quails typically have short rounded wings that enable them to spring into full flight instantly when disturbed in their hiding places.
45.典型的鵪鶉都長有短而圓的翅膀，憑此他們可以在受驚時一躍而起，飛離它們的躲藏地。
46. According to anthropologists, the earliest ancestors of humans that stood upright resembled chimpanzees facially, with sloping foreheads and protruding brows.
46.根據(jù)人類學(xué)家的說法，直立行走的人的鼻祖面部輪廓與黑猩猩相似，額頭后傾，眉毛突出。
47. Not until 1866 was the fully successful transatlantic cable finally laid.
47.直到1866年第一條橫跨大西洋的電纜才完全成功的架通。
48. In his writing, John Crowe Ransom describes what he considers the spiritual barrenness of society brought about by science and technology.
48. John Crowe Ransom在他的著作中描述了他認為是由科學(xué)技術(shù)給社會帶來的精神貧困。
49. Children with parents whose guidance is firm, consistent, and rational are inclined to possess high levels of self-confidence.
49.父母的教導(dǎo)如果堅定，始終如一和理性，孩子就有可能充滿自信。
50. The ancient Hopewell people of North America probably cultivated corn and other crops, but hunting and gathering were still of critical importance in their economy.
50.北美遠古的Hopewell人很可能種植了玉米和其他農(nóng)作物，但打獵和采集對他們的經(jīng)濟貿(mào)易仍是至關(guān)重要的。

51. Using many symbols makes it possible to put a large amount of inFORMation on a single map.
51.使用多種多樣的符號可以在一張地圖里放進大量的信息
52. Anarchism is a term describing a cluster of doctrines and attitudes whose principal uniting feature is the belief that government is both harmful and unnecessary.
52.無政府主義這個詞描述的是一堆理論和態(tài)度，它們的主要共同點在于相信政府是有害的，沒有必要的。
53. Probably no man had more effect on the daily lives of most people in the Untied States than did Henry Ford a pioneer in automobile production.
53.恐怕沒有誰對大多數(shù)美國人的日常生活影響能超過汽車生產(chǎn)的先驅(qū)亨利.福特。
54. The use of well-chosen nonsense words makes possible the testing of many basic hypotheses in the field of language learning.
54.使用精心挑選的無意義詞匯，可以檢驗語言學(xué)科里許多基本的假定。
55. The history of painting is a fascinating chain of events that probably began with the very first pictures ever made.
55.優(yōu)化歷史是由一連串的迷人事件組成，其源頭大概可以上溯到最早的圖畫。
56. Perfectly matched pearls, strung into a necklace, bring a far higher price than the same pearls told individually.
56.相互般配的珍珠，串成一條項鏈，就能賣到比單獨售出好得多的價錢。
57. During the eighteenth century, Little Turtle was chief of the Miami tribe whose territory became what is now Indiana and Ohio.
57.十八世紀時，“小烏龜”是邁阿密部落的酋長，該部落的地盤就是今天的印第安那州和俄亥俄州。
58. Among almost seven hundred species of bamboo, some are fully grown at less than a foot high, while others can grow three feet in twenty-four hours.
58.在竹子的近七百個品種中，有的全長成還不到一英尺，有的卻能在二十四小時內(nèi)長出三英尺。
59. Before staring on a sea voyage, prudent navigators learn the sea charts, study the sailing directions, and memorize lighthouse locations to prepare themselves for any conditions they might encounter.
59.謹慎的航海員在出航前，會研究航向，記錄的燈塔的位置，以便對各種可能出現(xiàn)的情況做到有備無患。
60. Of all the economically important plants, palms have been the least studied.
60.在所有的經(jīng)濟作物中，棕櫚樹得到的研究最少。
61. Buyers and sellers should be aware of new developments in technology can and does affect marketing activities.
61.購買者和銷售者都應(yīng)該留意技術(shù)的新發(fā)展，原因很簡單，因為技術(shù)能夠并且已經(jīng)影響著營銷活動。
62. The application of electronic controls made possible by the microprocessor and computer storage have multiplied the uses of the modern typewriter.
62.電腦儲存和由于電子微處理機得以實現(xiàn)的電控運用成倍的增加了現(xiàn)代打字機的功能。
63. The human skeleton consists of more than two hundred bones bound together by tough and relatively inelastic connective tissues called ligaments.
63.人類骨骼有二百多塊骨頭組成，住些骨頭石油堅韌而相對缺乏彈性的，被稱為韌帶的結(jié)蒂組連在一起。
64. The pigmentation of a pearl is influenced by the type of oyster in which it develops and by the depth, temperature, and the salt content of the water in which the oyster lives.
64.珍珠的色澤受到作為其母體牡蠣種類及牡蠣生活水域的深度，溫度和含鹽度的制約。
65. Although mockingbirds superbly mimic the songs and calls of many birds, they can nonetheless be quickly identified as mockingbirds by certain aural clues.
65.盡管模仿鳥學(xué)很多種鳥的鳴叫聲惟妙惟肖，但人類還是能夠依其聲音上的線索很快識別它們。
66. Not only can walking fish live out of water, but they can also travel short distances over land.
66.鲇魚不僅可以離開水存活，還可以在岸上短距離移動。
67. Scientists do not know why dinosaurs became extinct, but some theories postulate that changers in geography, climate, and sea levels were responsible.
67.科學(xué)家不知道恐龍為何絕種了，但是一些理論推斷是地理，氣候和海平面的變化造成的。
68. The science of horticulture, in which the primary concerns are maximum yield and superior quality, utilizes inFORMation derived from other sciences.
68.主要目的在于豐富和優(yōu)質(zhì)的農(nóng)藝學(xué)利用了其他科學(xué)的知識。
69. Snow aids farmers by keeping heart in the lower ground levels, thereby saving the seeds from freezing.
69.雪對農(nóng)民是一種幫助，因為它保持地層土壤的溫度，使種子不致凍死。
70. Even though the precise qualities of hero in literary words may vary over time, the basic exemplary function of the hero seems to remain constant.
70.歷代文學(xué)作品中的英雄本色雖各有千秋，但其昭世功力卻是恒古不變的。
71. People in prehistoric times created paints by grinding materials such as plants and clay into power and then adding water.
71.史前的人們制造顏料是將植物和泥土等原料磨成粉末，然后加水。
72. Often very annoying weeds, goldenrods crowd out less hardy plants and act as hosts to many insect pests.
72.***花通常令人生厭，它擠走不那么頑強的植物，并找來很多害蟲。
73. Starting around 7000 B.C., and for the next four thousand years, much of the Northern Hemisphere experienced temperatures warmer than at present.
73.大約從公元前七千年開始，在四千年當中，北半球的溫度比現(xiàn)在高。
74. When Henry Ford first sought financial backing for making cars, the very notion of farmers and clerks owning automobiles was considered ridiculous.
74.當亨利.福特最初制造汽車為尋求資金支持時，農(nóng)民和一般職員也能擁有汽車的想法被認為是可笑的。
75. Though once quite large, the population of the bald eagle across North America has drastically declined in the past forty years.
75.北美禿頭鷹的數(shù)量一度很多，但在近四十年中全北美的禿頭鷹數(shù)量急劇下降。
76. The beaver chews down trees to get food and material with which to build its home.
76.水獺啃倒樹木，以便取食物并獲得造窩的材料。
77. Poodles were once used as retrievers in duck hunting, but the American Kennel Club does not consider them sporting dogs because they are now primarily kept as pets.
77.長卷毛狗曾被用作獵鴨時叼回獵物的獵犬，但是美國Kennel Club卻不承認它們?yōu)楂C犬，因為它們現(xiàn)在大多數(shù)作為寵物飼養(yǎng)。
78. As a result of what is now know in physics and chemistry, scientists have been able to make important discoveries in biology and medicine.
78.物理學(xué)和化學(xué)的一個成果是使得科學(xué)家們能在生物學(xué)和醫(yī)學(xué)上獲得重大發(fā)現(xiàn)。
79. The practice of making excellent films based on rather obscure novels has been going on so long in the United States as to constitute a tradition.
79.根據(jù)默默無聞的小說制作優(yōu)秀影片在美國由來已久，已經(jīng)成為傳統(tǒng)。
80. Since the consumer considers the best fruit to be that which is the most attractive, the grower must provide products that satisfy the discerning eye.
80.因為顧客認為最好的水果應(yīng)該看起來也是最漂亮的，所以種植者必須提供能滿足挑剔眼光的產(chǎn)品。
81. Television the most pervasive and persuasive of modern technologies, marked by rapid change and growth, is moving into a new era, an era of extraordinary sophistication and versatility, which promises to reshape our lives and our world.
81.電視，這項從迅速變化和成長為標志的最普及和最有影響力的現(xiàn)代技術(shù)，正在步入一個新時代，一個極為成熟和多樣化的時代，這將重塑我們的生活和世界。
82. Television is more than just an electronics; it is a means of expression, as well as a vehicle for communication, and as such becomes a powerful tool for reaching other human beings.
82.電視不僅僅是一件電器；它是表達的手段和交流的載體并因此成為聯(lián)系他人的有力工具。
83. Even more shocking is the fact that the number and rate of imprisonment have more than doubled over the past twenty years, and recidivism------that is the rate for re-arrest------is more than 60 percent.
83.更讓人吃驚的事實是監(jiān)禁的數(shù)目和比例在過去的二十年中翻了一番還有余，以及累犯率——即再次拘押的比例——為百分之六十強。
84.William Rainey Harper lured him to the new university of Chicago, where he remained officially for exactly a generation and where his students in advanced composition found him terrifyingly frigid in the classroom but sympathetic and understanding in their personal conferences.
84.他的教書生涯始于麻省理工學(xué)院，但是William Rainey Harper把他吸引到了新成立的芝加哥大學(xué)。他在那里正式任職長達整整一代人的時間。他的高級作文課上的學(xué)生覺得他在課上古板得可怕，但私下交流卻富有同情和理解。
85. The sloth pays such little attention to its personal hygiene that green algae grow on its coarse hair and communities of a parasitic moth live in the depths of its coat producing caterpillars which graze on its mouldy hair. Its muscles are such that it is quits incapable of moving at a speed of over a kilometer an hour even over the shortest distances and the swiftest movement it can make is a sweep of its hooked arm.
85.樹獺即不講究衛(wèi)生，以至于它粗糙的毛發(fā)上生出綠苔，成群的寄生蛾生長在它的皮毛深處，變成毛毛蟲，并以它的臟毛為食。她的肌肉不能讓他哪怕在很短的距離以內(nèi)以每小時一公里的速度移動。它能做的最敏捷的動作就是揮一揮它彎曲的胳膊。
86. Artificial flowers are used for scientific as well as for decorative purposes. They are made from a variety of materials, such as way and glass, so skillfully that they can scarcely be distinguished from natural flowers.
86.人造花卉即可用于科學(xué)目的，也可用于裝飾目的，它們可以用各種各樣的材料制成，臂如蠟和玻璃；其制作如此精巧，幾乎可以以假亂真。
87. Three years of research at an abandoned coal mine in Argonne, Illinois, have resulted in findings that scientists believe can help reclaim thousands of mine disposal sites that scar the coal-rich regions of the United States.
87.在伊利諾州Angonne市的一個廢棄煤礦的三年研究取得了成果，科學(xué)家們相信這些成果可以幫助改造把美國產(chǎn)煤區(qū)弄得傷痕累累的數(shù)千個舊煤場。
88. When the persuading and the planning for the western railroads had finally been completed, the really challenging task remained: the dangerous, sweaty, backbreaking, brawling business of actually building the lines.
88.當有關(guān)西部鐵路的說服和規(guī)劃工作終于完成后，真正艱難的任務(wù)還沒有開始；即危險，吃力，需要傷筋動骨和吵吵嚷嚷的建造這些鐵路的實際工作。
89. Because of the space crunch, the Art Museum has become increasingly cautious in considering acquisitions and donations of art, in some cases passing up opportunities to strengthen is collections.
89.由于空間不足，藝術(shù)博物館在考慮購買和接受捐贈的藝術(shù)品是越來越慎重，有些情況下放棄其進一步改善收藏的機會。
90. The United States Constitution requires that President be a natural-born citizen, thirty-five years of age or older, who has lived in the United States for a minimum of fourteen years.
90.美國憲法要求總統(tǒng)是生于美國本土的公民，三十五歲以上，并且在美國居住了至少十四年。
91. Arid regions in the southwestern United States have become increasingly inviting playgrounds for the growing number of recreation seekers who own vehicles such as motorcycles or powered trail bikes and indulge in hill-climbing contests or in caving new trails in the desert.
91.美國西部的不毛之地正成為玩耍的地方，對越來越多擁有摩托車或越野單車類車輛的，喜歡放縱于爬坡比賽或開辟新的沙漠通道的尋歡作樂者具有不斷增長的吸引力。
92. Stone does decay, and so tools of long ago have remained when even the bones of the man who made them have disappeared without trace.
92.石頭不會腐爛，所以以前的(石器)工具能保存下來，雖然它們的制造者已經(jīng)消失的無影無蹤。
93. Insects would make it impossible for us to live in the world; they would devour all our crops and kill our flocks and herds, if it were not for the protection we get from insect-eating animals.
93.昆蟲就將會使我們無法在這個世界上居�。蝗绻�我們沒有受到以昆蟲為食的動物的保護，昆蟲就會吞嚼掉我們所有的莊稼并殺死我們飼養(yǎng)的禽獸。
94. It is true that during their explorations they often faced difficulties and dangers of the most perilous nature, equipped in a manner which would make a modern climber shudder at the thought, but they did not go out of their way to court such excitement.
94.確實，他們在探險中遇到了極具威脅性的困難和危險，而他們的裝備會讓一個現(xiàn)代登山者想一想都會渾身顫栗。不過他們并不是刻意去追求刺激的。
95. There is only one difference between an old man and a young one: the young man has a glorious future before him and old one has a splendid future behind him: and maybe that is where the rub is.
95.老人和年輕人之間只有一個區(qū)別：年輕人的前面有輝煌的未來，老年人燦爛的未來卻已在它們身后。這也許就是困難之所在。
96. I find young people exciting. They have an air of freedom, and they have not a dreary commitment to mean ambitions or love comfort. They are not anxious social climbers, and they have no devotion to material things.
96.我們位年強人振奮。它們帶有自由的氣息，他們不會為狹隘的野心和貪婪享受而孜孜以求。他們不是焦慮的向上爬的人，他們不會對物質(zhì)性的東西難舍難分。
97. I am always amazed when I hear people saying that sport creates goodwill between the nations, and that if only the common peoples of the world could meet one another at football or cricket, they would have no inclination to meet on the battlefield.
97.每次我聽說體育運動能夠在國家間建立起友好感情，說世界各地的普通人只要能在足球場或板球場上相遇就會沒有興趣在戰(zhàn)場上相遇的話，我都倍感詫異。
98. It is impossible to say simply for the fun and exercise: as soon as the question of prestige arises, as soon as you feel that you and some larger unit will be disgraced if you lose, the most savage combative instincts are around.
98.沒有可能僅僅為了娛樂或鍛煉而運動：一旦有了問題，一旦你覺得你輸了你和你所屬團體會有失體面時，你最野蠻的好斗本能就會被激發(fā)出來。
99. It has been found that certain bats emit squeaks and by receiving the echoes, they can locate and steer clear of obstacles------or locate flying insects on which they feed. This echo-location in bats is often compared with radar, the principle of which is similar.
99.人們已經(jīng)發(fā)現(xiàn)，某些蝙蝠發(fā)出尖叫聲并靠接受回響來鎖定和避免障礙物——或者找到它們賴以為生的昆蟲。蝙蝠這種回響定位法常拿來和原理與之很相近似的雷達相比。
100. As the time and cost of making a clip drop to a few days and a few hundred dollars, engineers may soon be free to let their imaginations soar without being penalized by expensive failure.
100.隨著芯片制造時間和費用降低到了幾天和幾百美元，工程師們可能很快可以任他們的想象馳騁而不會被昂貴的失敗所懲罰。