托福听力背景材料之地球之外的生命
【听力资料】详解托福听力背景知识之地球环境学类
详解托福听力背景知识之地球环境学类在托福听力的备考过程中，想要提分自己的反应速度，除了不断的练习和提升自己的词汇量之外，听力背景材料知识的累积也会为自己的托福听力反应速度带来很大的帮助。
那么，在以下内容中，我们就为大家带来详解托福听力场景之地球环境学类。
一、概述这一学科要求考生们要关注一些时事，并且扩大自己知识面，开拓视野，可以和地理地质学科一起关注。
☆大气环境，例如赤道无风带，大气环流，全球气候变化。
☆地面环境，例如风能，地下水的研究与保护。
☆海洋环境，例如海底热液，潮汐能。
☆其他话题，可能和天文学，生物学，地理地质学等产生交叉。
在此，考生最好能积累背景知识，多浏览一些原汁原味的报刊杂志，比如Scientific Americans、NationalGeographical等等，多积累相关词汇，熟悉发音。
当然，刚才也提到了，新托福听力段子所涉及的话题往往千变万化且有所交叉，考生在熟悉背景知识的同时也要打牢基础，培养快速辨音能力和短时记忆能力，才能以不变应万变。
二、案例分析请看一个地球环境学的经典案例：E.G.TPO17 Milankovitch Hypothesis听力原文：1) Ok, so we have been talking about theories that deal with the effects ofhuman activity on the climate. But today I’d like to talka little bit aboutother theories that canexplain variations in climate. And one of the best-knownis called the Milankovitch HypothesisQ:What is the lecture mainly about?AA hypothesis that explains how changes in Earth’s motions affectclimate.BA hypothesis that explains why the shape of earth’s orbit varies overtime.CReasons it is difficult to find evidence to support hypotheses about theclimate.DAnalyses of the accuracy of data collected in different ways.分析：这是一道简单的主旨题。
托福听力背景材料
托福听力背景材料——天文学(1宇宙与星系随着更强大望远镜的发明和科学技术的进步, 人类开始逐步深入探索宇宙的奥秘。
宇宙有多老 ? 宇宙中是否还有其他生命体 ? 宇宙有多大 ? 根据哈勃望远镜测算到宇宙的年龄是:130亿年到 170亿年之间。
所来一个偶然的发明, 使人们接收到宇宙微波辐射背景, 这就推算出宇宙的年龄是 137亿年, 这项技术因此还得了诺贝尔奖。
而在学科上, 也出现了一个新的学科——天体生物学。
天体生物学(astrobiology是天文学和生物学的交叉学科。
这个学科主要研究陨石中的微生物。
而这些微生物是可以随着陨石在不同的行星 (Planets之间转移的。
宇宙过于浩瀚,故而,天文学家需要划分出一些区域进行研究。
星系、星云、星群、星族、星座都是被划分出来的研究区域。
其中, 星系是最大的区域, 比如我们地球所处的银河系就是众多星系中的一个。
然而, 早期望远镜没有现在这么发达, 科学家还常常把星系误判断为星云, 比如现在我们银河系的邻居——大、小麦哲伦星云其实是星系。
星系与星系之间存在互相作用并进行吞噬, 银河系吸引临近的星系就像地球和月亮间的潮汐力吸引一样。
银河系会以它强烈的引力进行吞噬。
银河系对这个星系是有影响的:一方面吸收了它的星球 ; 另一方面改变了它的形状, 拉长它的形状最终破坏它。
天文学家还发现银河系中的某些缺金属元素的“高速星云” , 这些高速星云中和了新星上形成的金属元素。
这些星云起着维持银河系中星云平衡以便生成新星的作用月球的南极艾特肯盆地 (TPO1. 南极 -艾特肯盆地 (South Pole-Aitken basin.简称为 SPAB月球上最大的环形山 , 同时也是太阳系内已知最大的 , 形成了 South Pole-Aitken basin(SPAB。
这个环形山位于月球的背面, 接近南极的 Aitken 盆地, 直径约 2, 500 千米, 深 12千米。
该盆地层略有升高丰度的铁,钛,和钍等化学元素。
托福听力高频主题
背景知识解析： 地质学(geology)是关于地球的物质组成、内部构造、外部特征、各层 圈之间的相互作用和演变历史的知识体系。地球的主要构造从里到外 依次为地核(core) 、地幔 (mantle)、地 壳 (crust)。托福听力地质学 部分涉及的理论体系主要有： 。
地质环境科学
1 . 板块构造学说(plate tectonics)。 全球的岩石圈可以分为六大板块(plate)， 板块与板块的交界处由于其相对移动发生碰撞(collision)和张裂(tension crack)，在板块碰撞的地方常形成山脉(mountain range) ，在板块张裂的地方 常形成裂谷(rift valley)和 海 洋 (ocean) 。上述地壳运动活跃地区很容易形成火 山( volcano)和地震(earthquake)， 必备词汇： 岩浆(lava)，摩 擦 ( fraction)，喷 发 (eruption)
B. Its dry climate limits how much information it can yield about water movement.
C. Its rainfall patterns and soil conditions are not typical of conditions in all regions.
Subsequent
后续
saturate
浸透的，饱和的
pollutant
污染
trap
困入
far reaching implicathy does the professor compare isotopes to fingerprints
A. To provide support for an argument B. To clarify a difficult concept C. To identify a problem with the research study D. To suggest a way to test a theory
英语中级听力：Finding Life Beyond Earth 寻找地球以外的生命(中英对照)
1、Finding Life Beyond Earth 寻找地球以外的生命Since early times, people have been fascinated with the idea of life existing somewhere else besides earth. Until recently, scientists believed that life on other planets was just a hopeful dream. But now they are beginning to locate places where life could form.很久以来，人们就被地球以外存在生命的观点强烈地吸引。
直到近期，科学家们都坚信外星生命的想法只不过是个有希望的梦想。
但是现在他们开始定位外星生命形成的位置。
In 1997, they saw evidence of planets near other stars like the sun. But scientists now think that life could be even nearer in our own solar system. One place scientists are studying very closely is Europa, a moon of Jupiter.在1997年，他们在像太阳这类其他恒星的行星上发现了证据。
可是，现在科学家认为外星生命甚至更接近我们，就存在于我们太阳系中。
科学家们正在仔细研究的这个地方是欧罗巴，是木星的卫星。
Space probes have provided evidence that Europa has a large ocean under its surface. The probes have also made scientists think that under its surface Europa has a rocky core giving off volcanic heat. Water and heat from volcanic activity are two basic conditions needed for life to form.太空探索提供的证据表明在欧罗巴的表层下蕴藏着一个巨大的海洋。
高中英语作文范文-地球外是否存在生物 Does Living Creatures Exist Outer the Earth
高中英语作文范文-地球外是否存在生物 Does Living Creatures Exist Outer the EarthPeople are wondering about if there are living creatures in other planets. Scientists have been searching for the answer all the time. Though the official never publishes any information about the existing of another life, most people believe that life exists in outer space. In the science fiction films, the directors try to search the space. They pictured the large galaxy and presented the audience how the aliens looked like. What's more, some documentaries also recorded themysterious signs that seemed to be left by the unknown creatures. As a result, the public believes that aliens have come to our planet, or they just pretend to be someone else, studying about human beings. With the development of technology, someday the scientists can go much further and solve the riddles, at that time, we can know more about life.人们一直想知道在其他行星是否有生物存在。
托福听力讲座典型话题分类主题罗列介绍
托福听力讲座典型话题分类主题罗列介绍托福听力讲座主题众多，但这些主题按照典型话题来分类的话打字可以分为艺术Arts，生命科学Life Science，自然科学Physical Science和社会科学Social Science四个大类。
下面就和大家分享托福听力讲座典型话题分类主题罗列介绍，来欣赏一下吧。
托福听力讲座典型话题分类主题罗列介绍：自然科学类和社会科学类托福听力讲座典型话题自然科学类主题介绍Weather and atmosphere(天气和大气)Oceanography(海洋学)Glaciers,glacial landforms,ice ages(冰川、冰川地形、冰河纪) Deserts.and.other.extreme.environments(沙漠和其他极端环境)Pollution,alternative energy,environmental policy(污染、替代能源、环境政策)Other planetsatmospheres(其他星球的环境)Astronomy and cosmology(天文学和宇宙学)Properties of light,optics(光的特性、光学)Properties of sound(声的特性)Electromagnetic radiation(电磁辐射)Particle physics(粒子物理学)Technology of TV,radio,radar(电视、广播和雷达技术)Chemistry of inorganic things(无机物的化学性质)Computer science(计算机科学)Seismology..(plate.structure,earthquakes,tectonics,continental.drift ,structure.of.volcanoes)(地震学：板块结构、地震、构造地质学、大陆漂移、火山结构)托福听力讲座典型话题社会科学类主题介绍Anthropology of nonindustrialized civilizations (非工业化文明社会的人类学)Early writing systems (早期文字系统)Historical linguistics (历史语言学)Business,management,marketing,accounting (商业、管理、市场、会计)TV/radio as mass communication (作为大众传媒的电视/电台)Social.behavior.of.groups,community.dynamics,communal beha-vior(群体的社会行为、群落动态、集群行为)Child development(儿童发展)Education(教育)Modern.history.(including.the.history.of.urbanization.and industrialization and their economic and social effects)(现代历史，包括城市化的历史及其带来的经济和社会影响)托福听力：对话conversation出题思路讲解托福听力对话类套路解析：去找老师的学生都是好学生在托福听力的对话中，好学生不一定成绩好，但是一定态度好，即：听老师话，乖乖跟着老师的建议走，老师让交论文的design plan/proposal就会认真去写，老师让把论文重新修改也会一边问一边改，老师说什么就是什么，老师最大，永远向老师低头。
托福听力背景知识：地质学
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文档下载后可定制修改，请根据实际需要进行调整和使用，谢谢!并且，本店铺为大家提供各种类型的经典范文，如演讲稿、总结报告、合同协议、方案大全、工作计划、学习计划、条据书信、致辞讲话、教学资料、作文大全、其他范文等等，想了解不同范文格式和写法，敬请关注!Download tips: This document is carefully compiled by this editor. I hope that after you download it, it can help you solve practical problems. The document can be customized and modified after downloading, please adjust and use it according to actual needs, thank you!In addition, this shop provides you with various types of classic sample essays, such as speech drafts, summary reports, contract agreements, project plans, work plans, study plans, letter letters, speeches, teaching materials, essays, other sample essays, etc. Want to know the format and writing of different sample essays, so stay tuned!托福听力背景知识：地质学地质学(geology)是托福听力考试中的常见话题，为了帮助大家备考这方面的托福听力，下面本店铺就给大家带来托福听力背景知识：地质学剖析。
雅思A类大作文真题范文：寻找地外生命是否有意义 2018-02-10： India
Some people want government should spent money looking for life on other planet however others think it is waste of public money when there are so many problems on earth, government should solve it.Discuss both views.范文1：People have differing views with regard to the areas where the public money should be invested in. Some people argue the government should spend money on searching alien lives on other planets so that human beings may find alternative planets to live in the future. Others, however, oppose this view and believe there are more important concerns on Earth waiting to be addressed.Supports believe that not only people’s everyday life but also the future of human race will therefore benefit from launching alien projects. It is a fact that practical technology has been advanced through space exploration. For instance, there are many inventions including pace makers and smoke detectors, which are lifesavers in people’s everyday life, are the by-products of space research. In addition, find a new planet with lives may ease people’s concern about energy depletion. Due to the significance of the growing vehicle numbers and the expansion of urbanisation, today’s demand for energy has increased on an unprecedented scale.However, the opponents argue that the government should have more important concerns to mitigate the problems on Earth. There still are many people in many areas of the world who are suffering from disease, hunger and extreme poverty. The government has its moral obligation to prioritise the public money to be spent on freeing these people from suffering. By providing them a safety net, those people in need can be able to receive basic medical treatment, better education and more job opportunities.In conclusion, while many people can benefit from the outcomes from alien life searching, more people can have a better life if the government can invest money in combating poverty. Therefore, I believe the government should give the financial prioritises to address the problems on the earth.范文2：The expenditure on space programs to search for life on other planets should be increased, according to some people, while others consider it is wastage of money as there are other serious issues to be addressed on earth. In my opinion, although priority should be given to immediate problems, a portion of budget should be invested in future safety i.e. space exploration.To begin with, searching life on other space bodies could be a contingent plan in the worst case because of increasing risk to life on earth. The necessary resources for life, such as air and water, are completely exploited that puts us on the risk of extinction if proper actions are not taken on time. Moreover, it is crystal clear bynow that planet is not livable for the same amount of time what we have already enjoyed on the earth. Thus, all the effort to make human as multi-planetary species by government as well as by private sector, such as Tesla organization, is justifiable.However, there are other serious issues on earth which needs immediate attention than future problems. Take for an example of global warming, if it is not controlled, the planet will be uninhabitable sooner than we expected. Besides, when common man struggling for proper meal and potable water, it is not advisable to spend millions of taxpayers money, which can utilized effectively to solve basic need scarcity, to chase a mirage. For instance, poor country, such as Spain, is spending half of their total GDP on space agency overlooking the needs of their people. Thus, budget for space exploration should be prioritized after carefully examining the economic status of the nation.In Conclusion, life exploration on other planes will be beneficial if nation can afford it but immediate problem should be given more priority. Thus, it is reasonable for developed countries compared to underdeveloped nations.。
现代大学英语精读5 unit 6 life beyond earth
National Geographic magazine National Public Radio's Morning Edition
Meanings of the Title
something astonishing had happened in the universe.”
Life Beyond Earth (Para. 1)
Para. 1 1.What do you think of the opening paragraph?
Does the author begin the article in a forceful way?
Life beyond Earth contains two meanings: A. there might be live organisms in the
universe. B. there might be intelligence or alien
civilizations out in the universe.
Life Beyond Earth (Para. 1)
2.What does the author mean by “life” in the first paragraph?
Life in the first paragraph means “that property of plants and animals which makes it possible for them to take in food, get energy from it, grow, adapt themselves to their surroundings, and reproduce their kind.
托福听力知识背景 地理
⼀、⼭ ⼭，⾸先要对于⼀些著名的⼭或⼭脉要有了解，如：Alps阿尔卑斯⼭、Amdes安第斯⼭脉、Rockies罗基⼭脉、Applachians阿巴拉奇亚⼭、Cascades卡斯卡达⼭脉、St.Helens圣海伦斯⼭等。
⼭的考点有以下⼏点： formation/age即形成⽅式和年代的概念。
考⽣需要对于数字有⾜够的敏感度，包括⾼度(height)、⻓度(length)、海拔(altitude)、年龄(age)等。
针对于⼭脉(mountain ranges)的形成⽅式，有两⼤原因。
⼀是，板块的挤压或碰撞(collision of tectonic plates)，考⽣需要知道两⼤学说，板块构造说(Plate Tectonic)和⼤陆漂移学说(Continental Drifting)。
对于地球构造的名词需要知道，地壳(crust)、地幔(mantle)、地核(core)。
⼆是，由于⽕⼭爆发(during volcanic eruption/action)。
volcano---eruption/erupt 关于⽕⼭，常⻅考点就是对于⽕⼭的分类(classification)。
按照喷发周期(eruption cycle)，我们可以将⽕⼭分为三⼤类：active volcano活⽕⼭、Inactive/ extinct volcane死⽕⼭、Dormant volcane休眠⽕⼭，也就是潜在的活⽕⼭。
按照喷发强度(eruption intensity)，或者是⽕⼭结构决定，我们可以将⽕⼭分为两⼤类：盾状⽕⼭(shield volcano)和复式⽕⼭(Composite volcano)。
盾状⽕⼭的特点是形状像盾牌，喷发周期短，喷发强度⼩。
⽽复式⽕⼭有很多层，所以导致⽕⼭的内部压强(pressure)⼤、密度(density)⼤，它的特点是喷发周期强，喷发强度⼤。
在做听⼒的时候，考⽣要注意听的⽅法：听⽕上的类型(type);听⽕上的位置(与⼭的关系---与哪个⼭相连)(location—other mountain);次⽣灾害(productive disasters)---⽕⼭灰(ash cloud/ volcanic ash)、地震(earthquake)、⼭崩(landslide)、雪崩(avalanche)、泥⽯流(mudslide)、杀⽣(kill creatures);听调查和调查者(survey&research reaults);听⽕⼭由静到动的过程(process) ⼆、湖 同样的，对于湖，考⽣需要对于五⼤湖有⼀个了解。
托福听力讲座典型话题分类主题罗列介绍
托福听力讲座典型话题分类主题罗列介绍托福听力讲座主题众多，但这些主题按照典型话题来分类的话打字可以分为艺术Arts，生命科学Life Science，自然科学Physical Science和社会科学Social Science四个大类。
下面就和大家分享托福听力讲座典型话题分类主题罗列介绍，来欣赏一下吧。
托福听力讲座典型话题分类主题罗列介绍：自然科学类和社会科学类托福听力讲座典型话题自然科学类主题介绍Weather and atmosphere(天气和大气)Oceanography(海洋学)Glaciers,glacial landforms,ice ages(冰川、冰川地形、冰河纪) Deserts.and.other.extreme.environments(沙漠和其他极端环境)Pollution,alternative energy,environmental policy(污染、替代能源、环境政策)Other planetsatmospheres(其他星球的环境)Astronomy and cosmology(天文学和宇宙学)Properties of light,optics(光的特性、光学)Properties of sound(声的特性)Electromagnetic radiation(电磁辐射)Particle physics(粒子物理学)Technology of TV,radio,radar(电视、广播和雷达技术)Chemistry of inorganic things(无机物的化学性质)Computer science(计算机科学)Seismology..(plate.structure,earthquakes,tectonics,continental.drift ,structure.of.volcanoes)(地震学：板块结构、地震、构造地质学、大陆漂移、火山结构)托福听力讲座典型话题社会科学类主题介绍Anthropology of nonindustrialized civilizations (非工业化文明社会的人类学)Early writing systems (早期文字系统)Historical linguistics (历史语言学)Business,management,marketing,accounting (商业、管理、市场、会计)TV/radio as mass communication (作为大众传媒的电视/电台)Social.behavior.of.groups,community.dynamics,communal beha-vior(群体的社会行为、群落动态、集群行为)Child development(儿童发展)Education(教育)Modern.history.(including.the.history.of.urbanization.and industrialization and their economic and social effects)(现代历史，包括城市化的历史及其带来的经济和社会影响)托福听力：对话conversation出题思路讲解托福听力对话类套路解析：去找老师的学生都是好学生在托福听力的对话中，好学生不一定成绩好，但是一定态度好，即：听老师话，乖乖跟着老师的建议走，老师让交论文的design plan/proposal就会认真去写，老师让把论文重新修改也会一边问一边改，老师说什么就是什么，老师最大，永远向老师低头。
托福听力常考学科背景知识
托福听力背景知识(一)Troy 特洛伊“荷马史诗”包括《伊利亚特》和《奥德赛》两部长诗，被认为是古希腊最伟大的作品，也是欧洲文学中最古老、最杰出的叙事诗。
相传史诗的作者是古希腊盲诗人荷马。
他生于爱奥尼亚（今土耳其西海岸），生存年代约是公元前8世纪的后半叶。
《伊利亚特》共24卷，15693行，记载了希腊联军攻陷特洛伊城的10年战争，而主要描述战争最后一年的一个事件，着重描绘了希腊英雄阿基里斯的的伟大形象。
相传在古希腊的弗提亚地方，有个叫珀琉斯的国王举行婚礼。
他邀请了奥林匹斯山上的众神出席，却把专管争吵的女神厄里斯给忘记了。
厄里斯便挑起是非，偷偷把一个写着“送给最美丽的女神”的金苹果放在了婚礼宴席上。
参加喜宴的天后赫拉、智慧女神雅典娜、爱与美之神阿芙罗狄蒂（即罗马神话中的维纳斯）都认为自己是美丽的，应该得到这个金苹果，于是争吵起来。
天神宙斯无法，只得让她们去特洛伊，让特洛伊王子帕里斯判定金苹果该给谁。
当3位女神见到帕里斯后，都争着向他许愿：赫拉愿给他权力和财宝；雅典娜愿给他胜利和智慧；阿芙罗狄蒂愿让他挑选世界上最美丽的女子为妻。
结果，帕里斯把金苹果判给了阿芙罗狄蒂。
阿芙罗狄蒂便与帕里斯约定帮他得到世界第一美女。
大约在公元前12世纪，希腊半岛上建立了许多小王国，斯巴达是其中的一个。
一天，斯巴达王宫来了两位尊贵的客人，他就是特洛伊国王普里阿摩斯和他的二儿子帕里斯。
特洛伊是小亚细亚半岛（今土耳其）上的一个小王国。
斯巴达国王米雷劳斯以隆重的礼节欢迎两位贵宾，连年轻的王后海伦也亲自出来接待。
海伦是当时全希腊最美丽的女人。
帕里斯禁不住看了她两眼，顿时动心。
海伦见了这位英俊的王子，也感到满心欢喜。
当晚，趁斯巴达国王外出的时候，帕里斯在阿芙罗狄蒂的帮助下，拐走了海伦，乘船逃回特洛伊。
蒙受奇耻大辱的斯巴达国王，立刻找到他的哥哥、另一个小国迈锡尼的国王阿加米农商量，决定向全希腊各王国求助。
于是，以阿加米农为统帅，组织了10万希腊联系，乘坐1013艘战船，越过爱琴海攻打特洛伊城。
托福听力考试背景知识综合辅导（六）
太阳系的⾏星九⼤⾏星通常按以下⼏个⽅法分类：根据组成： 固态的由⽯头构成的⾏星：⽔星，⾦星，地球和⽕星： 固态⾏星主要由岩⽯与⾦属构成，⾼密度，⾃转速度慢，固态表⾯，没有光环，卫星较少。
较⼤的⽓态⾏星：⽊星，⼟星，天王星和海王星： ⽓态⾏星主要由氢和氦构成，密度低，⾃转速度快，⼤⽓层厚，有光环和很多卫星。
冥王星。
根据⼤⼩: ⼩⾏星：⽔星，⾦星，地球，⽕星和冥王星。
⼩⾏星的直径⼩于13000公⾥。
巨⾏星：⽊星，⼟星，天王星和海王星。
巨⾏星的直径⼤于48000公⾥。
⽔星和冥王星有时被称作次⾏星(lesser planets)（不要与次级⾏星(minor planets)－－⼩⾏星的官⽅命名－－相混乱）。
巨⾏星有时被称为⽓态⾏星。
根据相对太阳的位置： 内层⾏星：⽔星，⾦星，地球和⽕星。
外层⾏星：⽊星，⼟星，天王星，海王星和冥王星。
在⽕星和⽊星之间的⼩⾏星带组成了区别内层⾏星和外层⾏星的标志。
根据相对地球的位置： 地内⾏星：⽔星和⾦星。
离太阳与地球较近。
地内⾏星看起来的如同地球上看有时不完整的⽉亮。
地球。
地外⾏星：⽕星到冥王星。
离太阳与地球较远。
地外⾏星看起来通常是完整的，或近乎完整的。
根据历史： 古典⾏星：⽔星，⾦星，⽕星，⽊星和⼟星。
史前即以得知 可⽤⾁眼观测 现代⾏星：天王星，海王星，冥王星。
近现代所发现 ⽤望远镜观测 地球未知点： 太阳系是怎样起源的？⼀般来说是由尘粒与⽓体的星云压缩形成的，但详情很不清楚。
⾏星系统如何与其它星系共处？已有了⽊星般⼤⼩的在附近轨道运动的对象的恒星的极好的证据。
组成固态⾏星的条件是什⼳？看起来地球这样的星体并不是独⼀⽆⼆的，但⽬前还没有直接证据证明这个或其它。
地球科学类
地球科学类:第一篇（地球interior）I'm glad you brought up the question of our investigations into the makeup of the Earth's interior. In fact --- since this is the topic of your reading assignment for next time --- let me spend these last few minutes of class talking about it. There were several important discoveries in the early part of this century that helped geologists develop a more accurate picture of the Earth's interior.The first key discovery had to do with seismic waves --- remember they are the vibrations caused by earthquakes. Well, scientists found that they traveled thousands of miles through the Earth's interior. This finding enabled geologists to study the inner parts of the Earth. You see, these studies revealed that these vibrations were of two types: compression --- or P --- waves and shear --- or S --- waves. And researchers found that P waves travel through both liquids and solids, while S waves travel only through solid matter.In 1906 a British geologist discovered that P waves slowed down at a certain depth but kept traveling deeper. On the other hand, S waves either disappeared or were reflected back, so he concluded that depth marked the boundary between a solid mantle and a liquid core. Three years later another boundary was discovered --- that between the mantle and the Earth's crust.There's still a lot to be learned about the Earth. For instance, geologists know that the core is hot. Evidence of this is the molten lava that flows out of volcanoes. But we're still not sure what the source of the heat is.第二篇（Climate）Today I want to talk about the Earth's last major climatic shift, at the end of the last ice age.But first, let's back up a moment and review what we know about climatic change in general. First, we defined "climate" as consistent patterns of weather over significant periods of time.In general, changes in climate occur when the energy balance of the Earth is disturbed. Solar energy enters the Earth's atmosphere as light and is radiated by the Earth's surface as heat. Land, water, and ice each affect this energy exchange differently. The system is so complex that, to date, our best computer models are only crude approximations and are not sophisticated enough to test hypotheses about the causes of climatic change.Of course, that doesn't keep us from speculating. For instance, volcanic activity is one mechanism that might affect climatic change. When large volcanoes erupt, they disperse tons of particles into the upper atmosphere, where the particles then reflect light. Since less light is entering the system of energy exchange, the result would be a cooling of the Earth's surface.Of course, this is just one possible mechanism of global climate change. In all probability, a complete explanation would involve several different mechanisms operating at the same time.第三篇（Minerals）I'd like to begin by thanking Dr. Kane for inviting me to be here today. Although I'm not ageologist, I have been collecting minerals for years. My collection is rally diverse because I've traveled all over the world to find them. Today I've brought a few specimens for you to see. After I discuss each one, I'll pass it around so that you can look at it more closely.As you know, feldspars are the most abundant minerals and are divided into a number of types. These first samples are orthoclases. Notice that they vary in color from white to pink to red. This glassy one is found in volcanic rock --- in fact, I found it in New Mexico on a collecting trip.This next sample that I'll pass around is a microcline mineral --- also called amazonstone. You can identify it by its bright green color. It's often used in jewelry and really is quite attractive.These final samples are all plagioclase feldspars. Many plagioclases are very rare, so I'm particularly proud of the variety in my collection.I've also brought a few slides of some large mineral samples, and if you'll turn out the light now, I'd like to show them to you.第四篇（能源fossil fuels）Today I want to discuss fossil fuels such as coat, oil, and natural gas. The term "fossil fuel" refers to the trapped remains of plants and animals in sedimentary rock. You see, living plants trap energy from the sun by the process of photosynthesis, and they store the energy in their chemical compounds. Most of that energy is released when the plant dies and decays. However, sometimes organic matter is buried before it decays completely. In this way some of the solar energy becomes trapped in rocks --- hence the name fossil fuel. Although the amount of organic matter trapped in any one growing season is small, the accumulated remains from millions of years are considerable. Because the accumulation rate is so slow --- millions of times slower than the rate at which we now dig up this organic matter and burn it for energy --- we must consider fossil fuels as nonrenewable resources. Tomorrow we'll be discussing alternatives to fossil fuels that can be renewed.第五篇（mountain）Not long ago, some of you may have read about a team of mountain-climbing scientists who helped to recalculate the elevation of the highest mountain in the world: Mt. Everest. Of course, the elevation of Mt. Everest was determined many years ago, using traditional surveying methods. But these scientists wanted to make a more precise measurement using a new method that takes advantage of recent advances in technology. It's called the Global Positioning System.The Global Positioning System uses 24 satellites that circle the Earth. Each of these satellites is constantly sending out signals. And each signal contains important information that can be used to determine the longitude, latitude, and elevation of any point on the Earth's surface.Well, in order to use this system to calculate Mt. Everest's elevation, scientists needed to put a special receiver on its summit to receive signals from the satellites. The problem with this was that, in the past, the receivers were much too heavy for climbers to carry. But now these receivers have been reduced to about the size and weight of a handheld telephone, so climbers were able to take a receiver to the top of Everest and, from there, to access the satellite system signals that wouldallow them to determine the precise elevation. And it turns out that the famous peak is actually a few feet higher than was previously thought.第六篇（地震）Now, you've been reading articles about the tremendous damage done to life and property by earthquakes. That's why seismologists have been working so hard to develop methods of earthquake prediction. We can now predict earthquake [assertively] fairly well, but the predictions only locate potential areas of danger. They don't predict the specific time and location at which an earthquake is likely to occur. Today I want to introduce to you three prediction models that have been developed.The first prediction model looks along earthquake fawlts, those cracks in the Earth's crust, to find what are known as seismic gaps. Seismic gaps are places where the fault has shown little or no seismic activity for a long time. This theory postulates that such places are due for a major shock.The second model relies on phenomena --- like ground flit. Using long cylindrical tubes containing water, observers noted that ground tilt tended to occur before major earthquakes. That led them to correctly predict the big Haicheng [HI CHUNG] quake of 1975 --- the first successful earthquake prediction scientists have ever made. A million people were evacuated from that Chinese city before the earthquake struck. Unfortunately, this method hasn't worked consistently, so we can't say it's been perfected.The third model is based on the theory that major earthquakes closely follow a series of minor ones. Starting with the measurements and timing of the smaller quakes, a complex formula calculates the "times of increased probability" of a much larger quake. Right now, this method, like the first method, cannot predict specific times and places, but that may change as it is further developed.For the moment, none of these models can predict with reasonable levels of confidence.第七篇（海洋学）One reason oceanographers analyze the sediment on the ocean floor is to see how long-terms changes in Earth's temperature have affected the depth of the ocean. By analyzing the remains of sea animals in old layers of ocean sediment, oceanographers can determine the depth of the ocean in the past. They've analyzed hundreds of such layers, including some from the coldest periods of Earth's history --- the ice ages. What they've found is that during the ice ages, the amount of water in the oceans decreased. Water levels in the ocean dropped by about four hundred feet. Water from the ocean evaporated and became frozen in continental glaciers, so it didn't drain back into the ocean. When temperatures eventually rose again, the glaciers melted, and the oceans returned to their former depths. Analysis of sedimentary data indicates that periods of glacial freezing and melting occurred in regular cycles of twenty thousand, forty thousand, and one hundred thousand years.Oceanographers are interested in the history of seawater levels because they hope to use this historical data in order to predict the possible effect that global warming could have on seawater levels. If industrial pollutants are capable of heating global temperatures to the point that glaciersbegin to melt, it is urgent for us to know precisely how high sea levels will rise as a result.第八篇（Road）he Old Canada Road is a long-lost trail between the Canadian province of Quebec and Maine, in the northeast corner of the United States. Yes, it really was lost, and finding it again was a complex process that involved state-of-the-art technology. How the location of the road was pinpointed was very interesting, and I'll return to it as soon as I've given you a little background information.The road was begun in 1817, a few years before Maine even became a state. At the time, Quebec was a major market for livestock, crops, and fish, so a road to Quebec was seen by officials in Maine as necessary for trade. For about 20 years, the movement of people and goods was mostly from Maine to Quebec, but then the trend reversed as thousands of Canadians immigrated to Maine to escape poor crops, a lack of jobs, and the threat of disease. I think it was a cholera epidemic.Besides these negative reasons, major building projects in Maine also made the state very attractive for the Canadians who needed work. I should stress, though, that immigration during that period went in both directions. In fact, the flow of people and goods went completely unhindered. There wasn't even a border post until around 1850. The people of the time saw Maine and Quebec as a single region, mainly because of the strong French influence, which is still evident in Maine today.Eventually, the road fell into disuse as a major railway was completed; finally, people simply forgot about it and that's how it came to be lost. This brings me back to the original topic.第九篇（能源）Scientists are always on the lookout for alternative sources of energy. Today we're going to discuss one that's so plentiful they say it could supply more energy than all the coal and oil in the world. It's found in something called gas hydrate and, believe it or not, that's a kind of ice.That's right. But the water in this ice was way down below the Earth's surface when it was frozen, so it was under a lot of pressure. And trapped inside the crystals of ice are individual molecules of methane --- that's what's in natural gas.All this makes gas hydrate pretty strange stuff. If you touch a match to a piece of this ice, it'll burst into flame. And when geologists bring a chunk of it up to the surface to study at normal air pressure and temperature, gas hydrate begins to hiss and bubble --- and in less than half an hour, the ice melts and the methane inside escapes into the air.Now, as you might guess, this can make gas hydrate kind of hard for miners to handle. And then there's the problem of where it's located --- in frozen arctic regions or in ocean waters off the Atlantic coast --- and up to a mile down.Environmentalists warn that mining it could even be disastrous. Offshore drilling could allowseawater to seep down into the huge icy deposits and release tons of methane up into the atmosphere. And methane, our listeners may recall, is a greenhouse gas that could really worsen the problem of global warming.So, gas hydrate may offer some interesting possibilities. But, with all these drawbacks, I'm not going to hold my breath waiting for it to fuel my furnace.第十篇（Great plain）Look at our topographical map and you'll see that the middle third of the North American continent --- from the Rocky Mountains almost to the Mississippi River --- is pretty flat. This is the Great Plains. This kind of area is sometimes called a prairie, sometimes a steppe. That's [ess-tee-ee-pee-pee- ee]. The defining features are level terrain, dry climate, and an absence of trees. The Great Plains are actually the former bed of shallow inland sea. Over millions of years, sediment left by glaciers, water, and wind smoothed out the dry sea bed.As I said, the Great Plaints are bordered on the west by the Rocky Mountains. And it's really the Rockies that are responsible for the formation of the grasslands. The mountains are so high that they block the heavy moist air traveling eastward form the Pacific Ocean. Lighter, drier air passes over the mountains. Until people intervened with irrigation and farms, only grass could grow on the dry, windy plain. In fact, we can divide the Great Plains into three zones. In the west, where it's driest and windiest, the grass is very short. In the eastern zone, there's more rain and grass grows as high as 360 centimeters. In the middle third, there's a mix of grass species that grow to an intermediate height.第十一篇（能源）Since we've been discussing alternative fuels lately, I wanted to pass on to you some information I read about a new fuel that's been in the news a lot lately. It's called A-21.It's composed of water and a chemical known as naphtha. It seems to be a very promising fuel because it's much cleaner than the gasoline that we use today. That's not to say that it doesn't pollute, but it is cleaner. A-21 isn't like some other alternative fuels that require completely new types of engines. A-21 still works in regular, everyday combustion engines --- like the ones in cars --- with only minor mechanical modifications. So changing over wouldn't be a big deal.You may doubt some of these claims as many researchers have. Some people feared that because it contains about 45 percent water it would freeze in the winter. But a small amount of antifreeze was added to it, and that seems to have solved the problem.A-21 has recently undergone street tests in buses in Reno, Nevada. So far it seems to work just fine. This is a good thing, especially in Nevada, because the state government there has passed a law requiring that a large percentage of vehicles in Nevada run on alternative fuels. A-21 should help.第十二篇（风tornado）The winds of a tornado are the most violent and destructive ones on Earth. Any of you who have seen one knows very well how frightening and powerful they are. What's interesting about them is that scientists don't actually know exactly why tornadoes occur.We do know, however, what happens when tornadoes are formed. As you remember, a front occurs when cool, dry air from the north meets warm, humid air coming from the south (from the Gulf of Mexico, for tornadoes in the United States). Where these air masses meet, a narrow zone of storm clouds develops, and thunderstorms, and sometimes tornadoes, occur.How is this violent weather produced? Well, a mass of warm, humid air rises very rapidly. As it rises, more warm air rushes in to replace it. This inrushing air also rises, and in some cases, especially when there is extreme thermal instability, begins to rotate. When this happens, the rotating air forms a tornado.Even if you've seen tornadoes only in movies, you know that they can demolish buildings in seconds. This is possible because when a tornado passes over a house, it sucks up air from around the house and so the air pressure outside the house drops rapidly. Inside, pressure remains the same. So, air pressure inside is greater than air pressure outside. The result is that the building explodes outward. Next, we'll talk a little bit about how new technological developments are being used to try to predict tornadoes.。
寻找地球以外的生命有什么意义英语作文
寻找地球以外的生命有什么意义英语作文The Search for Extraterrestrial Life: Why it MattersIntroductionThe question of whether or not we are alone in the universe has captivated the human imagination for centuries. The idea of discovering life beyond Earth has been the subject of countless works of science fiction, from novels and films to television shows and video games. But how likely is it that we will actually find evidence of extraterrestrial life? And what would the implications be if we did? In this essay, we will explore the significance of the search for extraterrestrial life and why it matters.Exploring the UnknownOne of the main reasons why the search for extraterrestrial life is so important is that it represents a quest to explore the unknown. As humans, we are naturally curious beings who are constantly seeking to expand our knowledge and understanding of the world around us. The discovery of life beyond Earth would provide us with a whole new realm of knowledge to explore and study. It would open up new possibilities for scientific research and discovery, and could even lead to insights that revolutionizeour understanding of biology, evolution, and the nature of life itself.Moreover, the search for extraterrestrial life represents a unique opportunity to expand our perspective and challenge our preconceived notions about the universe. As the famous astronomer Carl Sagan once said, "The universe is a pretty big place. If it's just us, seems like an awful waste of space." By seeking out life beyond Earth, we are acknowledging the vastness and diversity of the cosmos, and humbling ourselves before the mysteries of the unknown.The Implications of DiscoveryBut perhaps the most significant reason why the search for extraterrestrial life matters is the profound implications that such a discovery would have for humanity. The mere existence of life beyond Earth would have far-reaching consequences for our understanding of our place in the universe, our beliefs about the nature of life and consciousness, and our sense of identity as a species.For one thing, the discovery of extraterrestrial life would challenge many of the assumptions and beliefs that underpin human civilization. It would force us to confront the fact that we are not unique or special in the grand scheme of things, butmerely one of countless forms of life that exist in the universe. This realization could have profound philosophical, cultural, and religious implications, shaking the foundations of many of the beliefs and values that have guided human society for millennia.Moreover, the discovery of extraterrestrial life could have practical implications for the future of humanity itself. If we were to find evidence of intelligent life beyond Earth, it could provide us with valuable insights into how other civilizations have evolved and adapted to their environments. This knowledge could help us to better understand our own place in the universe and to navigate the challenges that lie ahead for our species, from climate change and resource depletion to the threat of nuclear war and global pandemics.ConclusionIn conclusion, the search for extraterrestrial life is a deeply meaningful and important quest that has the potential to transform our understanding of the universe and our place within it. By seeking out life beyond Earth, we are engaging in a bold and ambitious exploration of the unknown, pushing the boundaries of human knowledge and imagination in ways that have the power to reshape our understanding of life, the universe, and everything in between. In the words of the latephysicist Stephen Hawking, "The discovery of extraterrestrial life would be the greatest discovery in human history. It would change our perceptions of ourselves and our place in the cosmos." And that, ultimately, is why the search for extraterrestrial life matters.。
英语听力材料《地球之外有生命吗》
英语听力材料《地球之外有生命吗》英语听力材料《地球之外有生命吗》地球之外有无生命直到今天都没有得到一个全体信服的答案。
你认为呢?接下来，让我们走进下面的英语听力材料。
Since early times, people have been fascinated with the idea of life existing somewhere else besides earth. Until recently, scientists believed that life on other planets was just a hopeful dream. But now they are beginning to locate places where life could form.很久以来，人们就被地球以外存在生命的观点强烈地吸引。
直到近期，科学家们都坚信外星生命的想法只不过是个有希望的梦想。
但是现在他们开始定位外星生命形成的位置。
In 1997, they saw evidence of planets near other stars like the sun. But scientists now think that life could be even nearer in our own solar system. One place scientists are studying very closely is Europa, a moon of Jupiter.在1997年，他们在像太阳这类其他恒星的行星上发现了证据。
可是，现在科学家认为外星生命甚至更接近我们，就存在于我们太阳系中。
科学家们正在仔细研究的'这个地方是欧罗巴，是木星的卫星。
Space probes have provided evidence that Europa has a large ocean under its surface. The probes have also made scientists think that under its surface Europa has a rocky core giving off volcanic heat. Water and heat from volcanic activity are two basic conditions needed for life to form.太空探索提供的证据表明在欧罗巴的表层下蕴藏着一个巨大的海洋。
地球外生物的探索与可能存在
感谢观看
THANKS
THE FIRST LESSON OF THE SCHOOL YEAR
研究微生物在太空中的生存状况，探索其在无重力、真空、辐射等极端环境下的 适应性。
微生物在火星等行星上的生存实验
通过模拟火星等行星的环境，研究微生物是否能在这些星球上存活和繁衍。
极端环境下的生命适应性研究
极端环境下的生命形式
研究在高温、低温、高盐度、高压等 极端环境下生命体的适应性，探索地 球生命的极限生存条件。
极端环境下的生命演化
通过模拟极端环境，研究生命在极端 环境下的演化过程，揭示地球生命的 起源和演化机制。
寻找地外生命的探测器与仪器
探和性能。
VS
仪器研发
开发能够检测地外生命迹象的仪器和设备 ，如光谱仪、质谱仪等，提高探测的灵敏 度和准确性。
对人类在宇宙中的地位的思考
人类在宇宙中的渺小与伟 大
探索地球外生物的可能性，让人们更加深刻 地认识到人类在宇宙中的渺小。然而，正是 这种渺小，让人类更加珍惜自己的存在，努 力发挥自己的智慧和创造力，成为宇宙中伟 大的存在。
人类对宇宙的认知与探索
探索地球外生物的过程，也是人类对宇宙认 知和探索的过程。这个过程将不断拓展人类 的视野和认知边界，让人类更加深入地了解
天文学家通过观察星空，对宇宙中可能存在的生命进行了初步猜想和推测。
古代哲学家和思想家对宇宙中生命的存在进行了探讨，提出了各种假说和理论。
早期的天文学家和科学家对地球外生命的探索主要基于哲学和宗教观念，缺乏科学 依据。
太空时代的探索与发现
随着太空时代的到来，人类开 始通过发射探测器和卫星来研 究宇宙中的生命迹象。
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地球外生命的证据 与发现
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托福听力背景材料之地球之外的生命
Saturn's largest moon, Titan, has a thick atmosphere. Clouds. Complex organic molecules. NASA has called it "one of the most Earth-like worlds we have found to date." With one glaring exception. "It's awfully cold down there. It's about 94 degrees Kelvin. Which means that water would be a rock."
土星最大的卫星是太阳神，太阳神有厚厚的大气层。
云是复杂的有机分子。
美国国家航空和宇
宙航行局称它为“我们迄今为止发现的和地球最相似的星球”。
例外就是，这里特别冷。
温度在94凯市摄氏度，这就意味着水会被冻成坚硬的石头。
Paulette Clancy, a chemical engineer at Cornell University. At temperatures that cold —minus 290 degrees Fahrenheit—one of the most basic biological structures, the cell membrane, can't exist. Because to form, the oily membranes depend on the presence of liquid water.
波莱特克兰西是康奈尔大学的一位化学工程师。
在温度为290华氏摄氏度时，最基本的细胞是
不能存活的。
因为油膜的形成依赖于液态的水。
That said, Titan does have plenty of liquid to go around—but it's liquid methane. So Clancy and her colleagues used computer models to determine whether any molecules on Titan might mimic the membrane-forming compounds here on Earth. Based on a catalog of organics observed by NASA's Cassini mission, they found a candidate: acrylonitrile. Its internal electrical charge distribution would allow it to self-assemble into membranes, just like phospholipids do here on Earth. It's similarly flexible and stable. And there's a lot of it on Titan.
据说太阳神这个星球上也有很多的液态物质，但这些是液态甲烷。
所以克兰西和她的同事们使
用计算机模型来确定太阳神上的分子是否能够模拟地球上的膜形成的化合物。
基于对有机物的目录
的观察，他们发现一个“候选人”: 丙烯腈。
其内部的电荷分布使其自组装成膜, 就像在地球上磷脂。
这是同样灵活和稳定。
有很多在泰坦。
它同样既灵活又稳定。
并且太阳神上也有很多。
Of course just because a cell membrane could form, does not mean it will. And actual life is a good deal more complicated than just a membrane. Still, Clancy says we might do
well to expand the search for life beyond just places with liquid water. "I think we tend to look for things that we know and understand. If we were more broad-minded we might find different kinds of life elsewhere. And maybe that would be fascinating too."
当然，仅仅因为一个可能形式细胞膜, 并不意味着它将形成细胞。
现实生活是一个比仅仅的一个膜要复杂的多。
不过,克兰西说我们扩大寻找生命不仅仅是寻找液态水的地方。
我认为我们倾向于寻找那些我们熟悉和了解的东西。
如果我们眼界足够开阔，我们可能在别的其他地方找到新的生命形式。
也许这是很有趣的。