3-TPO精选20篇第三季（11-15）

IBT-SAT 小马过河—专业备考社区 小马托福 TPO 听力精选二十篇系列（第三季） 使用 1 个月托福听力 25 分以上的飞跃——小马托福 TPO 听力精选二十篇系列 http://bbs.xiaoma.com/forum-viewthread-tid-84578-fromuid-254284.html 第一季（1-5 篇）地址在这里下载： http://dl.xiaoma.com/dl/topic/ad13fb68d2d5434b86ddad6805def771 第二季（6-10 篇）地址在这里下载： http://dl.xiaoma.com/dl/topic/3d0c0611815b4555bc5c6675ca534b22 第三季目录 （十一）地球科学——geologic time periods地质时期 （十二）地球科学——Lechuguilla Cave龙舌兰洞 （十三）生物学——foraging behavior among beavers 海狸 的觅食行为 （十四）生物学——North American wood frog 北美树蛙 （十五）历史——the role of spices 香料的作用 IBT-SAT 小马过河—专业备考社区 本篇音频下载地址： http://dl.xiaoma.com/dl/topic/47d53798c1354935bf95c9e7d9a49fc4 （十一）地球科学——geologic time periods地质时期 Narrator: Listen to part of a lecture in a geology class. 1. What is the lecture mainly about? A. Recognizing when one geologic epoch ends and another begins B. How geologists determine the age of Earth C. Whether humans have affected Earth’s climate D. Identifying elements that affect the formation of sediment layers 2. Why does the professor mention the Pleistocene epoch? A. To explain how sediments change during an ice age B. To give an example of a well-defined geologic epoch C. To describe how certain environmental conditions affect erosion rates D. To describe the factors that influence the naming of geologic epochs 3. Researchers study sediment in order to learn about the characteristics of past geologic epochs. What does the professor say that sediment reveals about a particular epoch? Click on 2 answers.  The climate on Earth then the sediment formed  The places on Earth with the highest amounts of rainfall  The level of the oceans at the time  The organisms that lived when the sediment formed 4. According to the professor, what is the significance of the year 1800 C.E? Click on 2 answers.  The human population reached 1billion  The Anthropocene epoch was first described.  Industrialization began to influence Earth’s environment  There was a significant change in the amount of sediment deposited around the world. 5. What does the professor imply about the spread of agriculture 8,000 years ago? A. It was the true beginning of the Holocene epoch. IBT-SAT 小马过河—专业备考社区 B. It was when greenhouse gases were at their lowest levels C. It was not a major cause of population growth D. It did not cause as big an environmental impact as some researchers say 6. What does the professor say about future researchers? A. They may not agree that humans have had an important effect on Earth’s surface B. They will not have reliable evidence of what is happening today C. They will determine when the Anthropocene epoch began D. They will make predictions about when the Anthropocene epoch will end Key： 1.A 2.B 3.AD 4.AC 5.D 6.C 听力原文： Professor As geologists, we examine layers of sediment on the Earth’s surface to approximate the dates of past geologic time periods. Ah sediment as you know is material like sand, gravel, fossil fragments that is transported by natural processes like wind , water flow or the movement of glaciers . So sediment is transported and then deposited and it forms layers on the Earth’s surface over time. We examine these layers to learn about different geologic time periods including when they began and ended. For example, from about 1.8 million years ago to around 11 thousand years ago was the Pleistocene epic. The Pleistocene epic was an ice age. During this epic, sediment was made by the kind of erosion and weathering that happens when the climate is colder, and part of those sediments are fossils of plants and animals that lived at that time. The Holocene epic followed the Pleistocene epic when the Earth’s climate warmed up around 11 thousand years ago. The Holocene epic is characterized by different sediments, ones that form when the climate is warmer. Because the climate changed, the types of plants and animals changed also. Holocene sediments contain remnants of more recent plants and animals, so it’s pretty easy to differentiate geologically between these two epics. Now there is growing evidence that the presence of humans has altered the earth so much that a new epic of geologic history has began – the Anthropocene epic, a new human-influenced epic. T his idea that we’ve entered a new Anthropocene epic was first proposed in 2002. The idea is that around the year 1800 CE the human population became large enough, around a billion people, that its activities started altering the environment. This was Administrator 高亮 Administrator 高亮 Administrator 高亮 IBT-SAT 小马过河—专业备考社区 also the time of the industrial revolution, which brought a tremendous increase in the use of fossil fuels such coal. The exploitation of fossil fuels has brought planet wide developments: industrialization, construction, uh, mass transport. And these developments have caused major changes like additional erosion of the Earth’s surface and deforestation. Also, things like the damming of rivers, has caused increased sediment production, not to mention the addition of more carbon dioxide and methane in the atmosphere. Naturally all these changes show up in recent sediments. And these sediments are quite different from pre year 1800 sediment layers. Interestingly there’s some speculation that humans started having a major impact on Earth much earlier, about 8000 years ago. That’s when agriculture was becoming widespread. Early farmers started clearing forests and livestock produced a lot of extra methane. But I want to stress this is just a hypothesis. The idea that early humans could have had such a major effect, well I’m just not sure we can compare it with the industrial age. Geologists in the far future will be able to examine the sediment being laid down today, whereas right now we can say that yes, human impact on the Earth is clear: It’ll be future researchers who have a better perspective and will be able to really draw a line between the Holocene and the Anthropocene epics. 原文翻译: 教授 作为地质学家，我们会通过检测地表的沉淀物层来估计过去的地质时期。嗯，就 像你们理解那样，沉淀物就是一些诸如沙子、碎石和化石碎片，他们被自然过程 转移，这些自然过程包括风、水流和冰川的运动。所以，沉淀物被转移然后被积 淀，久而久之形成了地表层。我们检测这些地表层以研究不同的地质时期，包括 每一个时期是何时开始何时结束。比如说，从 18亿年前到 11000年前，是更新 世。更新世是一个冰川时期。在这个时期，沉淀物是由天气较冷时候的侵蚀和风 化作用形成的，其中有些沉淀物是生活在那个时期的动物和植物的化石。在更新 世之后的是一个较暖和的完新世，这个时期大约是在 11000 年前。代表完新世 的是另外一种在天气较暖和是生活的植物沉淀物。由于天气的变化，动植物的种 类也发生了变化。完新世的沉淀物包含更多近期动植物的遗体，所以从地质上是 很好分辨出这两个时期的。 目前越来越多的证据显示人类对 地球的影响之大使得地球开始了一个新的地质 历史——人类世，一个全新的人类影响的时期。这个我们人类进入的全新的时期 最早是在 2002年提出的。这个观点认为在公元 1800年，人类数量达到十亿， 这个数目已经大到开始改变环境。这同时是工业革命的时期，这个时期开始大量 的使用化石燃料，比如说煤炭。对化石燃料的开采带来了全球性的发展：工业化， 建筑，嗯，公共交通运输。同时这些发展也引起了一些主要的变化，比如说地表 Administrator 高亮 IBT-SAT 小马过河—专业备考社区 的额外侵蚀和森林采伐。并且，像在河流中修建水坝之类的事情使得沉淀物增加， 更不用说大气中二氧化碳和甲烷的增加了。 这些变化自然是在近期的沉淀物中出现的。并且这些沉淀物与 1800年之前的沉 淀物层非常的不同。值得关注的是，一些人认为人类更早就开始对地球产生主要 影响了，大概在 8000年前。也就是在农业开始变得普遍时。早期的农民开始砍 伐森林并且家畜会产生许多额外的甲烷。不过我想强调一下，这个仅仅是一个假 说。关于早期人类产的主要影响，嗯，我个人认为我们无法将那种影响与工业时 代的相提并论。将来的地质学家会去检验我们今天留下来的沉积物，然而我们现 在能够说，是的，人类对地球的影响是非常清晰的：需要将来有更好砍伐的研究 者们来真正划出完新世和人类世之间的界限。 IBT-SAT 小马过河—专业备考社区 本篇音频下载地址： http://dl.xiaoma.com/dl/topic/6f1993c3e0b24813990bddf4f828ad1f （十二）地球科学——Lechuguilla Cave龙舌兰洞 1. What is the main purpose of the lecture? A. To explain the various ways that sulfuric acid is involved in the formation of caves B. To describe caves and other geologic formations in U.S. national parks C. To use Lechuguilla Cave as an example of how most caves form D. To discuss the formation and characteristics of an unusual type of cave 2. The professor mentions parts of the process involved in the formation of Lechugilla Cave Indicate which of the statements below describe part of the process Click in the coned box for each phrase Yes No Gypsum residue accumulated to form decorative structures Gas generated by bacteria reacted with gypsum deposits Hydrogen sulfide gas mixed with underground water Acid dissolved parts of the limestone Bactena fed on underground oil Flowing surface water enlarged the cracks in the limestone 3. According to the professor, what substance found in surface water is important for the formation of typical limstone caves? A. Gypsum B. Oxygen C. Car borne acid D. Sulfuric acid 4. What does the presence of gypsum in Lechuguilla Cave indicate? A. The cave was not formed by flowing water B. The cave is no longer forming IBT-SAT 小马过河—专业备考社区 C. Bacteria are present in high concentrations inside the cave D. No type of acid was involved in the formation of the cave 5. What can be inferred from be fact that Lechuguilla Cave is no longer forming? A. The cave has stopped attracting visitors B. The cave no longer contains any limestone C. The air in the cave is safer to breathe now than it was in the past D. Gypsum deposits inside the cave are growing thicker 6. What does the professor mean when he says this A. Lechuguilia Cave is not completely absent of water B. Lechuguilia Cave is not totally safe to explore C. Water long ago flowed through Lechuguilia Cave D. Scientists do not agree about how Lechuguilia Cave was formed Key： 1. D 2. Yes No Yes Yes Yes No 3. C 4. A 5. C 6. A 目解析： 1. What is the main purpose of the lecture? A. To explain the various ways that sulfuric acid is involved in the formation of caves. B. To describe caves and other geologic formations in U.S. national parks. C. To use Lechuguilla Cave as an example of how most caves form. D. To discuss the formation and characteristics of an unusual type of cave. 相关原文 Now there are some pretty interesting caves in parts of the western United States, especially in national parks. There is one part that has over a hundred caves, including some of the largest ones in the world. One of the most interesting ones is called Lechuguilla Cave. 解析 教授一开始就提到这次讲座的主题，Lechuguilla洞穴，后面就针对这种特殊的 洞穴的成形和特点进行了阐述，所以选D。 正确 D 2. Yes or No Gypsum residue accumulated to form decorative structures. Gas generated by bacteria reacted with gypsum deposits. Hydrogen sulfide gas mixed with underground water. Acid dissolved parts of the limestone. IBT-SAT 小马过河—专业备考社区 Bacteria fed on underground oil. Flowing surface water enlarged the cracks in the limestone. 相关原文 Below the water table and rock is oil. Bacteria feed on this oil and release hydrogen sulfide gas. This gas is hydrogen sulfide, rises up and mixes with oxygen in the underground water that sits in the cracks and fissures in the limestone. And when hydrogen sulfide reacts with the oxygen in the water, the result of that is sulfuric acid, Ok? Sulfuric acid eats away at limestone very aggressively. So you get bigger cracks and then passageway is being formed along the openings in the rock and it’s all underground. There’s such variety there like nothing anywhere else in the world, some of them are elaborate looking, like decorations. And a lot of them are made of gypsum and could be up to 20 feet long. It’s pretty impressive. 解析 细节，针对文中一个主要段落，关于洞穴如何形成的，以及里面的石膏残余物起 装饰作用，可以判断各项句子。 正确答案 YNYYYN 3. According to the professor, what substance found in surface water is important for the formation of typical limestone caves? A. Gypsum B. Oxygen C. Carbonic acid D. Sulfuric acid 相关原文 Also, in surface water, there is a weak acid, carbonic acid, not sulfuric acid but carbonic acid that helps dissolve the rock. With a little help from this carbonic acid, moving water forms most of the world’s limestone caves. 解析 教授说，在流动的水中还含有一种很弱的酸，碳酸，这种算帮助流水形成了绝大 多数石灰岩洞，因此选C。 正确答案 C 4. What does the presence of gypsum in Lechuguilla Cave indicate? A. The cave was not formed by flowing water. B. The cave is no longer forming. C. Bacteria are present in high concentrations inside the cave. D. No type of acid was involved in the formation of the cave. 相关原文 And, as we know, gypsum is soluble in water. So if there were flowing water in IBT-SAT 小马过河—专业备考社区 the cave, it would dissolve the gypsum. This is part of what led us to the realization that Lechuguilla is in that small group of waterless caves. 解析 由于石膏是溶于水的，而在Lechuguilla有大量石膏的存在，这就说明它是一个 无水洞穴。 正确答案 A 5. What can be inferred from the fact that Lechuguilla Cave is no longer forming? A. The cave has stopped attracting visitors. B. The cave no longer contains any limestone. C. The air in the cave is safer to breathe now than it was in the past. D. Gypsum deposits inside the cave are growing thicker. 相关原文 And Lechuguilla is pretty much dormant now. It’s not really forming any more. But, there is other ones like it, for example, in Mexico, that are forming. And when cave researchers go to explore them, they see and smell, the sulfuric acid and gases of...er...phew...now, something else, think of rotten eggs. And, it’s not just the smell. Explorers even need to wear special masks to protect themselves from the gases in these caves. 解析 教授说Lechuguilla已经休眠了，然后提到类似还没有休眠的洞穴，里面硫化氢 气体的味道有毒且刺激，需要特殊面具保护，而Lechuguilla已经可以随意出入 了，也就是说，没有硫化氢气体继续形成洞穴，因此选C。 正确答案 C 6. What does the professor mean when he says this: A. Lechuguilla Cave is not completely absent of water. B. Lechuguilla Cave is not totally safe to explore. C. Water long ago flowed through Lechuguilla Cave. D. Scientists do not agree about how Lechuguilla Cave was formed. 相关原文 Dry as a bone. Well, that might be a bit of an exaggeration. But it’s safe to say that it’s sulfuric acid and not moving water that formed Lechuguilla cave and those few other ones like it. 解析 教授说洞穴里就像骨头一样干，但说完后就觉得说的有点儿夸张。后面就解释说 实际上Lechuguilla洞穴并不完全是没有水的，所以选A。 正确答案 A IBT-SAT 小马过河—专业备考社区 词汇： limestone：石灰岩 sulfuric acid：硫酸 permeate：渗透，穿过，渗入 crack：裂缝 fissure：裂缝，裂开 hydrogen sulfide：硫化氢 eat away：侵蚀 passageway：通道 dissolve：溶解，分解 exaggeration：夸张，夸张法 residue：残留，残余 gypsum：石膏 soluble：可溶的 dormant：冬眠的 mask：面具 elaborate：精致的，复杂的 听力原文： Narrator: Listen to a part of lecturer in a geology class. Professor: Now there are some pretty interesting caves in parts of the western United States, especially in national parks. There is one part that has over a hundred caves, including some of the largest ones in the world. One of the more interesting ones is called Lechuguilla Cave. Lechuguilla has been explored a lot in recent decades. It’s a pretty exciting place I think. It was mentioned only briefly in your books. So can anyone remember what it said? Ellen? Male student: It’s the deepest limestone cave in the U.S.? Professor: That’s right. It’s one of the longest and deepest limestone caves not just in the country but in the world. Now, what else? Male student: Well, it was formed because of sulfuric acid, ght? Professor: That’s it. Yeah, what happens is you have deep underground oil deposits and there are bacteria. Here let me draw a diagram. surface Administrator 高亮 IBT-SAT 小马过河—专业备考社区 rock rock and water oil and bacteria Part of the limestone rock layer is permeated by water from below. Those curly lines are supposed to be cracks in the rock. Below the water table and rock is oil. Bacteria feed on this oil and release hydrogen sulfide gas. This gas is hydrogen sulfide, rises up and mixes with oxygen in the underground water that sits in the cracks and fissures in the limestone. And when hydrogen sulfide reacts with the oxygen in the water, the result of that is sulfuric acid, Ok? Sulfuric acid eats away at limestone very aggressively. So you get bigger cracks and then passageway is being formed along the openings in the rock and it’s all underground. Ah yes, Paul? Male student: So that water...it’s not flowing, right? It’s still? Professor: Yes, so there are two kinds of limestone caves. In about 90 percent of them, you have water from the surface, streams, waterfall or whatever - moving water that flows through cracks found in limestone. It’s the moving water itself that wears away at the rock and makes passageways. Also, in surface water, there is a weak acid, carbonic acid, not sulfuric acid but carbonic acid that helps dissolve the rock. With a little help from this carbonic acid, moving water forms most of the world’s limestone caves. When I was researching this for a study a few years ago, I visited a couple of these typical limestone caves, and they were all very wet, you know, from streams and rivers. This flowing water carved out the caves and the structures inside them. Male student: But not Lechuguilla? Professor: Dry as a bone. Well, that might be a bit of an exaggeration. But it’s safe to say that it’s sulfuric acid and not moving water that formed Lechuguilla cave and those few other ones like it. In fact, there is no evidence that flowing water has even gone in or out of the cave. So, it’s like a maze. You have passageways all around. There are wide passages, narrow ones at all different depths, like underground tunnels in the limestone. And, since they were created underground and not from flowing surface water, not all these passageways have an opening to the outside world. And.. .and there is other evidence that flowing water wasn’t involved in Lechuguilla. We’ve said that sulfuric acid dissolves limestone, right, and forms the passageways? What else does sulfuric acid do? Paul? Administrator 高亮 Administrator 高亮 IBT-SAT 小马过河—专业备考社区 Male student: Ah, leaves a chemical residue and... Female student: Gypsum, right? Professor: Yep, you’ll find lots of gypsum deposited at Lechuguilla. And, as we know, gypsum is soluble in water. So if there were flowing water in the cave, it would dissolve the gypsum. This is part of what led us to the realization that Lechuguilla is in that small group of waterless caves. And Lechuguilla is pretty much dormant now. It’s not really forming any more. But, there is other ones like it, for example, in Mexico, that are forming. And when cave researchers go to explore them, they see and smell, the sulfuric acid and gases of...er...phew...now, something else, think of rotten eggs. And, it’s not just the smell. Explorers even need to wear special masks to protect themselves from the gases in these caves. OK? Paul. Male student: Yeah, how about what these caves look like on the inside? Professor: Well, the formations.. .there is really something. There’s such variety there like nothing anywhere else in the world, some of them are elaborate looking, like decorations. And a lot of them are made of gypsum and could be up to 20 feet long. It’s pretty impressive. 原文翻译： 教授 目前在美国西部的部分地区，特别是在国家公园有许多非常有趣的洞穴。其中有 一个地方有超过一百个洞穴，包括一些世界上最大的洞穴。其中比较有趣的叫做 龙舌兰洞穴。在最近的几十年间，许多人都探索了龙舌兰。我想那一定是一个令 人激动的地方。在你们的课本中只是对它进行了简单的介绍。那么有人记得书本 上讲了什么么？Ellen？ 男学生 它是不是美国最深的石灰岩洞穴？ 教授 是的。它不仅仅是美国，并且是全世界最长、最深的洞穴。还有什么呢？ IBT-SAT 小马过河—专业备考社区 男学生 嗯，它是由硫酸形成的？ 教授 对了！实际上那里有最深的地下石油储备和细菌。让我来给你们画一幅图吧。 部分石灰岩层下面的水会不断的渗透石灰岩。那些弯曲的线应该是岩石中的裂 痕。在水层和岩石的下面是石油。细菌以石油为生同时释放出硫化氢气体。这种 硫化氢气体上升，与在岩石层裂缝间地下水中的氧气混合。那么当硫化氢气体与 水中的氧气反应时，产生了硫酸，对么？硫酸会很快地腐蚀石灰岩。所以，裂缝 越来越大，并且沿着岩石的开口和所有的地下形成通道。Paul？什么问题？ 男学生 那么，水是不流动的吧?水应该是静止的吧？ 教授 是的，有两种类型的石灰岩洞穴。其中 90%的石灰岩洞穴，在他们的表面都有 水，溪流，瀑布，任何能够在石灰岩缝隙中流动的水。是流动的水本身腐蚀岩石 并且形成了通道。同时，在水的表面，有一种弱酸，碳酸，是碳酸而不是硫酸溶 解了岩石。在碳酸的帮助下，流动的水形成了世界上大多数的石灰岩洞穴。我在 多年前做一个关于这方面的研究时，我游走了许多这种典型的石灰岩洞穴，他们 都非常的潮湿，主要是溪水和河流的原因。这些流动的水雕琢了这些洞穴以及他 们内部的结构。 男学生 但龙舌兰不是这样，对么？ 教授 像骨头一样的干燥。嗯，可能有一些夸张了。不过的确是硫酸而非流动的水形成 了龙舌兰洞穴的，并且与其他的都不相同。实际上，我们根本找不到曾经有流动 的水流入或者流出洞穴的证据。嗯，就像一个迷宫，到处都是通道。那里有很宽 阔的通道，而比较窄的通道都有不同的深度，就像石灰岩中的隧道一样。并且由 于他们都是在地下形成的，并非通过地表流动的水，所以不是所有的通道都有同 享外面的开口。嗯，其实还有其他证据能够证明龙舌兰中没有流动的水。我们说 过了硫酸溶解石灰岩并且形成通道，对么？那么硫酸还能干什么呢？Paul? 男学生 呃，留下一些化学残留物？ 女学生 是石膏，对么？ 教授 对的，你再龙舌兰能够发现许多石膏沉淀物。并且，我们知道的，石膏是在水中 IBT-SAT 小马过河—专业备考社区 可溶的。所以如果洞穴中有流动的水，那么石膏应该会溶解的。这一点也是使我 们意识到龙舌兰是属于一小部分的无水的洞穴。龙舌兰现在基本上是静止的。它 其实已经不再形成了。不过，在墨西哥有一个与它相似的洞穴正在形成。所以， 当洞穴研究者去探索他们的时候，他们看到和闻到，硫酸和各种气体。。。嗯，就 像，就像发霉的鸡蛋一样。并且，不仅仅是气味。探索者甚至需要戴面具来保护 他们自己不受其他的伤害。Paul？ 男学生 是的，那么这些洞穴的内部是什么样的呢？ 教授 嗯，它的构造啊，确实值得一提。那里面多种多样，世界上没有别的地方可以与 它相提并论，他们其中一些精致的，就像装饰一样。其中许多都是由石膏形成， 并且最多可能有 20英尺长。确实令人惊奇。 IBT-SAT 小马过河—专业备考社区 本篇音频下载地址： http://dl.xiaoma.com/dl/topic/df6bc3516b494665bb26488a6c3ce 0c8 （十三）生物学——foraging behavior among beavers 海狸 的觅食行为 1. What is the lecture mainly about? A. Different foraging strategies among animals B. Methods beavers use to gather building materials C. Decisions beavers make about where to live D. Choices beavers face when foraging 2. What difference between aspen tree