托福TPO听力文本翻译Lecture2(上)

【托福听力备考】TPO3听力文本——Lecture 2对于很多学生来说，托福TPO材料是备考托福听力最好的材料。

相信众多备考托福的同学也一直在练习这套材料，那么在以下内容中我们就为大家带来托福TPO听力练习的文本，希望能为大家的备考带来帮助。

Lecture 2 Film historyNarrator：Listen to part of a lecture in a film history class.Professor：Okay, we’ve been discussing films in the 1920s and 30s, and how back then film categories, as we know them today, had not yet been established. We said that by today’s standards, many of the films of the 20s and 30s would be considered hybrids, that is, a mixture of styles that wouldn’t exactly fit into any of today’s categories. And in that context, today we are going to talk about a film-maker who began making very unique films in the late 1920s. He was French, and his name was Jean Painlevé.Jean Painlevé was born in 1902. He made his first film in 1928. Now in a way, Painlevé’s films conform to norms of the 20s and 30s, that is, they don’t fit very neatly into the categories we use to classify films today. That said, even by the standards of the 20s and 30s, Painlevé’s films were a unique hybrid of styles. He had a special way of fusing, or some people might say, confusing, science and fiction. His films begin with facts, but then they become more and more fictional. They gradually add more and more fictional elements. In fact, Painlevé was known for saying that science is fiction.Painlevé was a pioneer in underwater film-making, and a lot of his short films focused on the aquatic animal world. He liked to show small underwater creatures, displaying what seemed like familiar human characteristics – what we think of as unique to humans. He might take a clip of a mollusk going up and down in the water and set it to music. You know, to make it look as if the mollusk were dancing to the music like a human being – that sort of thing. But then he suddenly changed the image or narration to remind us how different the animals are, how unlike humans.He confused his audience in the way he portrayed the animals he filmed, mixing up our notions of the categories human and animal. The films make us a little uncomfortable at times because we are uncertain about what we are seeing. It gives him films an uncanny feature: the familiar made unfamiliar, the normal made suspicious. He liked twists, he liked the unusual. In fact, one of his favorite sea animals was the seahorse because with seahorses, it’s the male that carries the eggs, and he thought that was great. His first and most celebrated underwater film is about the seahorse.Susan, you have a question?Student 1：But underwater film-making wasn’t that unusual, was it? I mean, weren’t there other people making movies underwater?Professor：Well, actually, it was pretty rare at that time. I mean, we are talking the early 1930s here.Student 1：But what about Jacques Cousteau? Was he like an innovator, you know, with underwater photography too?Professor： Ah, Jacques Cousteau. Well, Painlevé and Cousteau did both film underwater, and they were both innovators, so you are right in that sense. But that’s pretty much where the similarities end.First of all, Painlevé was about 20 years ahead of Cousteau. And Cousteau’s adventures were high-tech, with lots of fancy equipment, whereas Painlevé kind of patchedequipment together as he needed it. Cousteau usually filmed large animals, usually in the open sea, whereas Painlevé generally filmed smaller animals, and he liked to film in shallow water.Uh, what else? Oh well, the main difference was that Cousteau simply investigated and presented the facts – he didn’t mix in fiction. He was a strict documentarist. He set the standard really for the nature documentary. Painlevé, on the other hand, as we said before, mixed in elements of fiction. And his films are much more artistic, incorporating music as an important element.John, you have a question?Student 2：Well, maybe I shouldn’t be asking this, but if Painlevé’s films are so special, so good, why haven’t we ever heard of them? I mean, everyone’s heard of Jacques Cousteau.Professor： Well, that’s a fair question. Uh, the short answer is that Painlev é’s style just never caught on with the general public. I mean, it probably goes back at least in part to what we mentioned earlier, that people didn’t know what to make of his films – they were confused by them, whereas Cousteau’s documentaries were very straightforward, met people’s expectations more than Painlevé’s films did. But you true film history buffs know about him. And Painlevé is still highly respected in many circles.。

托福听力tpo46lecture1、2、3、4原文+题目+答案+译文Lecture1 (2)原文 (2)题目 (4)答案 (6)译文 (6)Lecture2 (8)原文 (8)题目 (10)答案 (12)译文 (12)Lecture3 (14)原文 (14)题目 (16)答案 (18)译文 (18)Lecture4 (19)原文 (19)题目 (22)答案 (24)译文 (24)Lecture1原文NARRATOR:Listen to part of a lecture in a biology class.FEMALE PROFESSOR:I'd like to continue our discussion of animal behavior and start off today's class by focusing on a concept we haven't yet touched upon—swarm intelligence.Swarm intelligence is a collective behavior that emerges from a group of animals,like a colony of termites,a school of fish,or a flock of birds.Let's first consider the principles behind swarm intelligence,and we'll use the ant as our model.Now,an ant on its own is not that smart.When you have a group of ants,however, there you have efficiency in action.You see,there's no leader running an ant colony. Each individual,each individual ant operates by instinctively following a simple set of rules when foraging for food.Rule number1:Deposit a chemical marker…called a pheromone.And rule2:Follow the strongest pheromone path.The strongest pheromone path is advantageous to ants seeking food.So,for example,when ants leave the nest,they deposit a pheromone trail along the route they take.If they find food,they return to the nest on the same path and the pheromone trail gets stronger—it's doubled in strength.Because an ant that took a shorter path returns first,its pheromone trail is stronger,and other ants will follow it, according to rule2.And as more ants travel that path,the pheromone trail gets even stronger.So,what's happening here?Each ant follows two very basic rules,and each ant acts on information it finds in its immediate local environment.And it's important to note: Even though none of the individual ants is aware of the bigger plan,they collectively choose the shortest path between the nest and a food source because it's the most reinforced path.By the way,a-a few of you have asked me about the relevance of what we're studying to everyday life.And swarm intelligence offers several good examples of how concepts in biology can be applied to other fields.Well,businesses have been able to use this approach of following simple rules when designing complex systems,for instance,in telephone networks.When a call is placed from one city to another,it has to connect through a number of nodes along the way.At each point,a decision has to be made:Which direction does the call go from here?Well,a computer program was developed to answer this question based on rules that are similar to the ones that ants use to find food.Remember,individual ants deposit pheromones,and they follow the path that is most reinforced.Now,in the phone network,a computer monitors the connection speed of each path, and identifies the paths that are currently the fastest—the least crowded parts of the network.And this information,converted into a numeric code,is deposited at the network nodes.This reinforces the paths that are least crowded at the moment. The rule the telephone network follows is to always select the path that is most reinforced.So,similar to the ant's behavior,at each intermediate node,the call follows the path that is most reinforced.This leads to an outcome which is beneficial to the network as a whole,and calls get through faster.But getting back to animal behavior,another example of swarm intelligence is the way flocks of birds are able to fly together so cohesively.How do they coordinate their movements and know where they're supposed to be?Well,it basically boils down to three rules that each bird seems to follow.Rule1:Stay close to nearby birds.Rule2:Avoid collision with nearby birds.And rule3:Move in the average speed and direction of nearby birds.Oh,and by the way,if you're wondering how this approach can be of practical use for humans:The movie industry had been trying to create computer-generated flocks of birds in movie scenes.The question was how to do it easily on a large scale?A researcher used these threerules in a computer graphics program,and it worked!There have also been attempts to create computer-generated crowds of people using this bird flocking model of swarm intelligence.However,I'm not surprised that more research is needed.The three rules I mentioned might be great for bird simulations,but they don't take into account the complexity and unpredictability of human behavior.So,if you want to create crowds of people in a realistic way,that computer model might be too limited.题目1.What is the lecture mainly about?A.Various methods that ants use to locate foodB.A collective behavior common to humans and animalsC.A type of animal behavior and its application by humansD.Strategies that flocks of birds use to stay in formation2.According to the professor,what behavior plays an important role in the way ants obtain food?A.Ants usually take a different path when they return to their nest.B.Ants leave chemical trails when they are outside the nest.C.Small groups of ants search in different locations.D.Ants leave pieces of food along the path as markers.3.What are two principles of swarm intelligence based on the ant example?[Click on2answers.]A.Individuals are aware of the group goal.B.Individuals act on information in their local environment.C.Individuals follow a leader's guidance.D.Individuals instinctively follow a set of rules.4.According to the professor,what path is followed by both telephone calls on a network and ants seeking food?A.The path with the least amount of activityB.The most crowded pathC.The path that is most reinforcedD.The path that has intermediate stopping points5.Why does the professor mention movies?A.To identify movie scenes with computer-simulated flocks of birdsB.To identify a good source of information about swarm intelligenceC.To emphasize how difficult it still is to simulate bird flightD.To explain that some special effects in movies are based on swarm intelligence6.What is the professor's attitude about attempts to create computer-generated crowds of people?A.She believes that the rules of birds'flocking behavior do not apply to group behavior in humans.B.She thinks that crowd scenes could be improved by using the behavior of ant colonies as a model.C.She is surprised by how realistic the computer-generated crowds are.D.She is impressed that computer graphics can create such a wide range of emotions.答案C B BD C D A译文下面听一段生物学讲座的片段。

托福听力tpo39lecture1、2、3、4原文+题目+答案+译文Lecture1 (2)原文 (2)题目 (4)答案 (6)译文 (6)Lecture2 (8)原文 (8)题目 (10)答案 (12)译文 (12)Lecture3 (14)原文 (14)题目 (16)答案 (18)译文 (18)Lecture4 (19)原文 (19)题目 (22)答案 (23)译文 (24)Lecture1原文NARRATOR:Listen to part of a lecture in a geology class.MALE PROFESSOR:Since Earth formed,some four and a half billion years ago,the number of minerals here has increased dramatically,from a few dozen relatively simple minerals early on…to over4,300kinds of minerals we can identify today—many of them wonderfully complex.A basic question of geology is how all these new minerals came into being.Well,recent studies have turned to biology to try to explain how this happens.Now,much of biology is studied through the lens of evolution.And the theory of evolution suggests that,as environments change—and inevitably they do—some organisms will have characteristics that allow them to adapt to those changes successfully…characteristics that help these organisms develop and survive and reproduce.And when environments become more complex—as tends to happen over time—those earlier adaptations,those variations…become the basis of yet other combinations and variations…and lead to ever more diverse and complex forms of life.So from fewer,simpler,and relatively similar forms of life billions of years ago,life on Earth has now become a dazzling array of diversity and complexity.Well,some geologists now want to apply this concept to explain mineral diversity too. The conditions that minerals are under are not constant.Conditions like temperature or pressure or chemical surroundings—these change—often in cycles,increasing and decreasing slowly over time.And as conditions change,minerals sometimes break down and their atoms recombine into totally new compounds,as part of a process some call mineral evolution.Now,minerals are not alive,of course,so this is not evolution in quite the same sense you'd have in living organisms.But there do appear to be some parallels.Living organisms not only adapt to their environment but also affect it—change theenvironment within which other organisms may then develop.Likewise,each new mineral also enriches the chemical environment from which lots of other,even more complex new minerals may be formed in the future.Beyond these similarities,though,what's really fascinating about mineral evolution is the way minerals apparently coevolve with living organisms.Uh,what do I mean by that?Well,it's maybe a billion years after Earth’s formation that we first see evidence of life.Of course,early life-forms were primitive—just tiny,single-celled microbes—but over time,they had a profound effect.Huge numbers of these microbes began producing food by photosynthesis,which,of course,also freed up enormous amounts of oxygen.And lots of that oxygen interacted with the atoms of existing minerals,creating rust out of iron,for instance,…reacting with a whole range of different metals to create lots of new minerals.Now,living organisms rely on minerals.But they not only take in some minerals as nutrients,they also excrete others as waste products...including what we call biominerals—minerals that form with the help of biological life.We can see geologic evidence of biomineral production in what are called stromatolites.Stromatolites look like wavy layers of sedimentary rock.But they're really fossils—fossils of the waste from microbial mats.Microbial mats are vast colonies of one-celled organisms…that were once the most prevalent form of life on Earth.And the study of stromatolites indicates that these ancient microbial mats interacted with minerals in the environment and left behind new compounds as waste products—biominerals like carbonates,phosphates,and silica.In fact,we’ve grown microbial mats in the laboratory,and,over time,they too have produced some of the same sorts of minerals found in stromatolites.Uh,you don't need to know the details of the process right now—we’re still figuring out just how it works,ourselves.But you might be interested to know that this concept of mineral evolution is being used in the search for evidence of life on other planets.The thinking is that if certainminerals occur here on Earth as a result of a biological process,and if we also find those same minerals on another planet,…this would suggest that life may have once existed there.But—just because a particular mineral is found on say,Mars or Venus—uh,we really shouldn't assume that whatever caused it to turn up there…must be the same process that formed that mineral here on Earth.题目1.What is the main purpose of the lecture?A.To explain how geologists identified the minerals present during Earth's formation.B.To explain why living organisms require certain minerals to survive.C.To explain the differences between simple and compound minerals.D.To explain a recent theory about mineral formation.2.What point does the professor make about the minerals present during Earth's formation?A.They were comparatively few of them.B.They were more complex than minerals formed on other planets.C.Most were not affected by temperature and pressure changes on early Earth.D.Some of them are no longer being formed naturally on Earth.3.What similarities does the professor point out between minerals and living organisms?[Click on2answers.]A.Both first appeared on Earth at approximately the same time.B.They both can be formed only in the presence of oxygen.C.They both have become more diverse and complex over time.D.Not only are they both shaped by their environment,but both also affect it.4.What are stromatolites?A.Fossils remains of microbial mats.yered deposits of iron-based minerals.yers of rock that indicate changes in Earth's pressure and temperature.D.Rock formations created when oxygen interacts with certain metals.5.Why does the professor talk about microbial mats?A.To explain why organisms tend to colonize near certain minerals.B.To describe how minerals can be created by living organisms.C.To illustrate the effects of geological processes on living organisms.D.To emphasize that evolving life depended on the presence of oxygen.6.What does the professor think about using evidence of minerals on another planet to determine whether life has existed there?A.He believes it is the most promising way to search for life on another planet.B.He doubts that complex minerals will ever be found on another planet.C.He is cautious about assuming that certain minerals indicate the presence of life.D.He is surprised that the technique was not suggested until recently.答案D A CD A B C译文旁白：请听一段地质学讲座的节选片段。

下面就让小编来为大家介绍一下托福听力TPO1原文中Lecture 2的文本内容吧，大家要好好把握，这些都是非常有价值的材料，希望能够给准备托福听力的同学带来帮助。

TPO 1 Lecture2GeologyListen to part of a lecture in a geology class.ProfessorOk, let’s get started. Great. Today I want to talk about a way in which we are able to determine how old a piece of land, or some other geologic feature is - dating techniques. I’m going to talk about a particular dating technique. Why? Good dating is key to good analysis. In other words, if you want to know how a land formation was formed, the first thing you probably want to know is how old it is. It’s fundamental.Uh… Take the Grand Canyon for instance. Now, we geologists thought we had a pretty good idea of how the Grand Canyon in the southwestern United States was formed. We knew that it was formed from sandstone that solidified somewhere between 150 and 300 million years ago. Before it solidified, it was just regular sand. Essentially it was part of a vast desert. And until just recently, most of us thought the sand had come from an ancient mountain range fairly close by that flattened out over time. That’s been the conventional wisdom among geologists for quite some time.But now we’ve learned something different, and quite surprising, using a technique called Uranium-Lead Dating. I should say that Uranium-Lead Dating has been around for quite a while. But there have been some recent refinements. I will get into this in a minute.Anyway, Uranium-Lead Dating has produced some surprises. Two geologists discovered that about half of the sand from the Grand Canyon was actually once part of the Appalachian Mountains. That’s really eye-opening news, since the Appalachian Mountain Range is, of course, thousands of kilometers to the east of the Grand Canyon. Sounds pretty unbelievable, right? Of course, the obvious question is how did that sand end up so far west? The theory is that huge rivers and wind carried the sand west where it mixed in with the sand that was already there.Well, this was a pretty revolutionary finding. Um… and it was basically because of Uranium-Lead Dating. Why? Well, as everyone in this class should know, we usually look at the grain type within sandstone, meaning the actual particles in the sandstone, to determine where it came from. You can do other things too,like look at the wind or water that brought the grains to their location and figure out which way it was flowing. But that’s only useful up to a point, and that’s not what these two geologists did.Uranium-Lead Dating allowed them to go about it in an entirely different way. What they did was: they looked at the grains of Zircon in the sandstone. Zircon is a material that contains radioactive Uranium, which makes it very useful for dating purposes. Zircon starts off as molten magma, the hot lava from volcanoes. This magma then crystallizes. And when Zircon crystallizes, the Uranium inside it begins to change into Lead. So if you measure the amount of Lead in the Zircon grain, you can figure out when the grain was formed. After that, you can determine the age of Zircon from different mountain ranges.Once you do that, you can compare the age of the Zircon in the sandstone in your sample to the age of the Zircon in the mountains. If the age of the Zircon matches the age of one of the mountain ranges, then it means the sandstone actually used to be part of that particular mountain range. Is everybody with me on that? Good. So, in this case, Uranium-Lead Dating was used to establish that half of the sandstone in the samples was formed at the same time the granite in the Appalachian Mountains was formed. So because of this, this new way of doing Uranium-Lead Dating, we’ve been able to determine that one of our major assumptions about the Grand Canyon was wrong.Like I said before, Uranium-Lead Dating has been with us for a while. But, um… until recently, in order to do it, you really had to study many individual grains. And it took a long time before you got results. It just wasn’t very efficient. And it wasn’t very accurate. But technical advances have cut down on the number of grains you have to study, so you get your results faster. So I’ll predict that Uranium-Lead Dating is going to become an increasingly popular dating method.There are a few pretty exciting possibilities for Uranium-Lead Dating. Here is one that comes to mind. You know the theory that earth’s continents were once joined together and only split apart relatively recently? Well, with Uranium-Lead Dating, we could prove that more conclusively. If they show evidence of once having been joined, that could really tell us a lot about the early history of the planet’s geology.独白：听一段地质学课程。

托福听力tpo63lecture1、2、3原文+题目+答案+译文Lecture1 (1)原文 (1)题目 (3)答案 (5)译文 (5)Lecture2 (7)原文 (7)题目 (9)答案 (11)译文 (11)Lecture3 (13)原文 (13)题目 (15)答案 (17)译文 (17)Lecture1原文Listen to part of a lecture in a geology class.Professor:OK.Before we begin,I wanna remind you that our field trip to Bryce canyon national park is this weekend.Remember the bus leaves early,five am,so don't forget to set your alarm clocks.I think you're all gonna enjoy getting out of the classroom and actually seeing some remarkable geologic phenomena.Now,while we're there,I want you to pay particular attention to two things.One obviously will be the sediment layers making up the rocks,since we've spent so much time onsedimentary rocks.Bryce canyon is a great place to see how millions of years have turned layers and layers of tightly packed sediment,mud particles,sand remains of plants and animals into rock.But you're also gonna see some fascinating rock shapes, formations that are the result of the weathering and the erosion processes that occur at Bryce canyon.There are two main processes that are important.The first one is a weathering process called frost wedge.Frost wedge a process that widens cracks in rocks in the wintertime.It begins with warm air or daytime sun melting the snow.As the snow turns into water,it seeps into the cracks that occur naturally in sedimentary rocks.At night,this water freezes in the cracks,but when water freezes,it expands quite a bit, which means that it prize cracks open,gradually,making them wider and breaking off a little bits in the process.Now,this thought freeze cycle can happen as many as two hundred times in a single year.So that makes it the most important weathering process at Bryce canyon.The other key processes is runoff,which is an erosion process.Runoff takes place in the summer.The parks in the desert said the grounds very dry.When it rains in late summer,the ground is too hard to absorb the water,so it runs off.And as it runs off, it carries away the gravel,the broken bits of rock created by cross wedge in the winter.So runoff is the main erosion process that alters the rock landscape in the park.And because these processes have occurred over thousands of years,some of the results can be pretty dramatic,like the giant corridors are passage ways that have developed within the rocks.These passage ways are known as slot canyons.Here's an example of one,not from the part we're going to.This one is actually in Australia,but the scale is typical.So these huge spaces started out as small cracks throughout the sedimentary rock,then thanks to millions of cycles across wedge and runoff.What used to be one big area of rock is now sort of two smaller areas of brought with the corridor in between.We'll have a chance to walk through some like this.These slot canyons are great places to explore,but let me just say,for any of you who aren't from around here,if you ever go on your own,make sure you check aweather forecast first.A sudden heavy rain can cause a flash flood in a slot canyon. So you want to know when it's safe to explore them.Unfortunately,it'll be dry this weekend.Now,these deep,narrow slots are pretty common.You might even have two of them very close to each other with only a thin wall of rock in between.Of course,frost wedge is still at work,so it starts wearing away at the front of the thin wall until you get a whole I mean a hole all the way through the wall,front to back.And this hole gets bigger and bigger.Once it's at least one meter in diameter,it's called a window.And eventually the weight on top of it is just too much,so the roof caves in and only the sides,sometimes it's just one side is left standing.These sides,which look a lot like collins,now are called Hudos.Here's a photo of something we'll be seeing.One of the things that makes Bryce canyon unique is that it has more Hudos than anywhere else in the world.Yes,Margot?Female student:Why is it so lumpy looking?You'd think it would be smoother.Professor:Well,remember,these are sedimentary rocks,so they have layers.Some layers are mostly limestone,and limestone erodes pretty quickly in the presence of any kind of acid.Now Bryce canyon in a very unpolluted area,but even,there the rain water has a little carbolic acid in it,which causes the limestone to erode.But other layers are made up of different types of sediment,which aren't so vulnerable to acid,so they don't erode as quickly.题目1.What is the lecture mainly about?A.The length of time required to produce sedimentary rocksB.The role of climate conditions in the creation of sedimentary rocksC.Some processes that produced a specific group of rock formationsD.Some unique geologic features found in canyons in the United States2.According to the professor,what is one characteristic that frost wedging and runoff share?A.Neither occurs in a desert.B.Neither is a frequent event.C.Both are weathering processes.D.Both are seasonal phenomena.3.Why does the professor show a picture of a slot canyon?A.To give students a sense of the size of a typical slot canyonB.To show students one of the places they will visit on their field tripC.To illustrate how many sediment layers are visible in a typical slot canyonD.To show how much slot canyons can vary based on local climate conditions4.What is the professor's attitude toward students exploring Bryce Canyon on their own?A.He worries that students may not know to take appropriate precautions if they go by themselves.B.He suspects that many students will not go on their own if such a trip requires them to get up early.C.He hopes that the class field trip will motivate students to visit Bryce Canyon on their own.D.He believes that students learn more from individual exploration than they dofrom being in a group.5.How is a hoodoo formed?A.Runoff produces large gravel deposits.B.Air pollution leads to a buildup of limestone.C.The roof of a rock window collapses.D.A flash flood washes away the base of a rock wall.6.According to the professor,what two factors explain why a hoodoo does not have a smooth shape?[Click on2answers.]A.The presence of acid in rainwaterB.The temperature swings between the summer and the winter seasonsC.The composition of the hoodoo's sedimentary layersD.The location of the cracks created by frost wedging答案C D A A C AC译文听一段地质学的讲座。

托福听力tpo51lecture1、2、3、4原文+题目+答案+译文Lecture1 (1)原文 (1)题目 (3)答案 (5)译文 (6)Lecture2 (7)原文 (7)题目 (10)答案 (12)译文 (12)Lecture3 (14)原文 (14)题目 (16)答案 (18)译文 (18)Lecture4 (20)原文 (20)题目 (22)答案 (24)译文 (24)Lecture1原文NARRATOR:Listen to part of a lecture in a botany class.FEMALE PROFESSOR:So,continuing with crop domestication,and corn—or,um, maize,as it's often called.Obviously it's one of the world's most important cropstoday.It's such a big part of the diet in so many countries,and it's got so many different uses,that it's hard to imagine a world without it.But because it doesn't grow naturally,without human cultivation,and because there's no obvious wild relative of maize…uh,well,for the longest time,researchers weren’t able to find any clear link between maize and other living plants.And that's made it hard for them to trace the history of maize.Now,scientific theories about the origins of maize first started coming out in the 1930s.One involved a plant called teosinte.Teosinte is a tall grass that grows wild in certain parts of Mexico and Guatemala.When researchers first started looking at wild teosinte plants,they thought there was a chance that the two plants—um, maize and teosinte—were related.The young wild teosinte plant looks a lot like the corn plant,and the plants continue to resemble each other—at least superficially—even when they're developed.But when the scientists examined the fruits of the two plants,it was a different story. When you look at ripe corn,you see row upon row of juicy kernels…um,all those tiny little yellow squares that people eat.Fully grown teosinte,on the other hand, has a skinny stalk that holds only a dozen or so kernels behind a hard,um,almost stonelike casing.In fact,based on the appearance of its fruit,teosinte was initially considered to be a closer relative to rice than to maize.But there was one geneticist,named George Beadle,who didn't give up so easily on the idea that teosinte might be…well…the“parent”of corn.While still a student in the1930s,Beadle actually found that the two plants had very similar chromosomes—very similar genetic information.In fact,he was even able to make fertile hybrids between the two plants.In hybridization,you remember,the genes of two species of plants are mixed to produce a new,third plant—a hybrid.And if this offspring—this hybrid—is fertile,then that suggests that the two species are closely related genetically.This new,hybrid plant looked like an intermediate,right between maize and teosinte.So,Beadle concluded that maize must've been developed over many years,uh,that it is a domesticated form of teosinte.Many experts in thescientific community,however,remained unconvinced by his conclusions.They believed that,with so many apparent differences between the two plants,it would have been unlikely that ancient—that prehistoric peoples could’ve domesticated maize from teosinte.I mean,when you think about it,these people lived in small groups,and they had to be on the move constantly as the seasons changed.So for them to selectively breed,to have the patience to be able to pick out just the right plants…and gradually—over generations—separate out the durable,nutritious maize plant from the brittle teosinte that easily broke apart…it's a pretty impressive feat,and you can easily see why so many experts would have been skeptical.But,as it turns out,Beadle found even more evidence for his theory when he continued his experiments,producing new hybrids,to investigate the genetic relationship between teosinte and maize.Through these successive experiments,he calculated that only about five specific genes were responsible for the main differences between teosinte and maize—the plants were otherwise surprisingly similar genetically.And more recently,botanists have used modern DNA testing to scan plant samples collected from throughout the Western Hemisphere.This has allowed them to pinpoint where the domestication of maize most likely took place—and their research took them to a particular river valley in southern Mexico.They've also been able to estimate that the domestication of maize most likely occurred about9,000 years ago.And subsequent archaeological digs have confirmed this estimate.In one site,archaeologists uncovered a set of tools that were nearly9,000years old.And these tools were covered with a dusty residue…a residue of maize,as it turns out…thus making them the oldest physical evidence of maize that we've found so far.题目1.What is the lecture mainly about?A.A research study that compares wild and domesticated plantsB.Problems with a commonly held hypothesis about the origin of teosinteC.Reasons why wild plants are usually unsuitable for agricultureD.The process used to identify the ancestor of a modern crop2.What evidence seemed to indicate that maize and teosinte are not related?A.Young teosinte plants do not physically resemble young maize plants.B.Preliminary DNA evidence indicated that teosinte was related to rice.C.Maize and teosinte usually grow in significantly different climates.D.Maize and teosinte have very different types of kernels.3.Why does the professor discuss hybrids?A.To explain how a geneticist confirmed that maize was widely grown9,000years agoB.To indicate the earliest method used by geneticists to identify plant originsC.To explain a method used to demonstrate a link between two plant speciesD.To describe how geneticists distinguish between wild plants and domesticated plants4.What was most researchers'initial view of George Beadle's theory about teosinte?A.They accepted it but questioned the evidence cited.B.They rejected it because of conflicting archaeological evidence.C.They questioned it because it implies that ancient farmers were sophisticatedplant breeders.D.They questioned it because genetic research was viewed with skepticism at that time.5.What did Beadle conclude about maize and teosinte?A.Both plants lack particular genes that are common in most domesticated plants.B.Both plants have particular genes that enable them to adapt to varying climates.C.Only a small number of genes are responsible for the differences between the two plants.D.The genetic composition of both plants is very similar to that of rice.6.According to the professor,why was the discovery of stone tools important?A.It proved that teosinte was simultaneously domesticated in multiple locations.B.It helped to confirm the period in which maize was first domesticated.C.It suggested that maize required farming techniques that were more complex than experts had previously assumed.D.It provided evidence that maize plants were used for more purposes than experts had previously assumed.答案D D C C C B译文旁白：请听一段植物学讲座的节选。

托福听力TPO19原文Lecture2下面就让小编来为大家介绍一下托福听力TPO19原文中Lecture2的文本内容吧，大家要好好把握，这些都是非常有价值的材料，同时，大家也可以登录前程百利论坛进行TPO练习辅导，希望能够给准备托福听力的同学带来帮助。

TPO19Lecture2AstronomyProfessor：So how many of you have seen the Milky Way,the Milky Galaxy in the sky? You,you have?Student：Yeah,I was camping,and there was no moon that night,it was super dark.Professor：Anybody else?Not too many.Isn’t that strange that the Milky Way is the galaxy that the planet earth is in,and most of us have never seen it?Now,what’s the problem here?Student：Light pollution,right?From street lights and stuff...Professor：Yes,Especially unshielded street light,you know,ones that aren’t pointed downward.Now,here’s an irony,the buiding we are in now,the astronomy building not far from our observatory,has unshielded lights.Student：So the problem is pretty widespread.Professor：It is basically beyond control,as far as expecting to view the night sky anywhere near city,I mean.I have lived around here my whole life.And I have never seen the Milky Way within city limits,and I probably never will.There is a price for progress, eh?But let’s think beyond light pullution,that’s only one kind of a technological advance that has interfered with astronomical research.Can anyone think of another?No?Ok,let’s look at it this way,we don’t only gain information by looking at the stars,for the past70years or so,we have also used radio astronomy1,which lets us study radio waves from the sky.Student：How can you observe radio waves?I mean,tell anything about the stars from that.Professor：Well,in optical astronomy,using a telescope and observing the stars that way,we rely on visible light waves.What we are seeing from earth is actually electromagnetic radiation that’s coming from stars.And just one part of it is visible light.But there are problems with that.When photons2and light waves hit objects in our atmosphere,water droplets,oxygen and nitrogen molecules,dust particles and so on.These objects are illuminated,they are lit up,and those things are also being lit by all our street lights,by the moon,all these ambient light.And on top of that,when that visible radiation bounces off those molecules,it scatters in all directions.And well,light from stars,even nearby in our own galaxy,doesn’t stand a chance against that.Basically the light bouncing off all these objects close to earth is brighter than what’s coming from the stars.Now,radiowaves are electromagnetic radiation that we can’t see.Nearly all astronomical objects in space emit radio waves,whether nearby stars,objects in far away galaxies,they all give off radio waves.And unlike visible light waves,these radio waves can get through the various gases and dusts in space,and through our own earth’s atmosphere comparatively easily.Student：Ok,then we might as well give up on optical astronomy and go with radio astronomy.Professor：Well,the thing is,with the radio astronomy,you can’t just set up a telescope in you backyard and observe stars.One problem is that radio waves from these far away objects, even though they can get through,are extremely faint.So we need to use radio telescopes, specially designed to receive these waves and then,well,we can use computers to create pictures based on the information we receive.Student：That sounds cool.So,how do they do that?Professor：Well,it is kind of like the same way a satellite dish3.receives its signal, if you are familiar with that.But radio telescopes are sometimes grouped together,is the same effect as having one big telescope to increase radio wave gathering power.And they use electronics,quite sophisticated.Yeah,it is neat how they do it,but for now why don’t we just stick with what we can learn from it.Some very important discoveries have been made by this technology,especially you consider that some objects in space give off radiowaves but don’t emit any light.We trouble discovering those sorts of bodies,much less studying them using just optical telescopes.Student：Well,If the radio waves are so good at getting throught the universe,what’s the problem?Professor：Well,answer this.How come people have to turn off their cell phones and all our electronic devices when an airplane is about to take off?Student：The phones interfere with the radio communication at the airport,right?Student：Oh,so our radio waves here on earth interfere with the waves from space?Professor：Yes,signal from radios,cell phones,TV stations,remote controls,you name it.All these things cause interference.We don’t think about that as often as we think about light pollution.But all those electrical gauges pollute the skies,just in a differen way.教授：嗯，你们中有多少人注意过银河系，观测过它的天象?你，你看过?学生：是的，教授。

【托福听力资料】托福TPO11听力文本——Lecture2【托福听力资料】托福TPO11 听力文本——Lecture 2众所周知，托福TPO材料是备考托福听力最好的材料。

相信众多备考托福的同学也一直在练习这套材料，那么在以下内容中我们就为大家带来托福TPO听力练习的文本，希望能为大家的备考带来帮助。

TPO11 Lecture 2 ArchitectureNarrator：Listen to part of a lecture in an Architecture Class.Professor：T oday, we are taking a little detour from the grand styles ofpublic architecture we’ve been studying to look at residential architectures inthe United States. Since this is something we can all identify with, I think it will help us see the relationship between the function of a structure and itsstyle or form. This has been an ongoing theme in our discussions, and we will begetting back to it in just a moment. But before we get started, I want you to take a moment to think: does anyone know what the single most popular style fora house in the United States is today? Bob?Student 1：“I bet it is the ranch-style house.”Professor：“Well, in this area, probably. But are we typical? Yes, Sue.”Student 2：“How about the kind of house my grandparents live in? They call it a Cape Cod.Professor：That’s the one. Here is a drawing of what we consider of aclassic Cape Cod house. These days, you see this style all over the United States. But it first showed up in U.S. northeast, in theNew England region, around the late 1600s. For those of you who don’t know the northeast coastalregion, Cape Cod is a peninsula, a narrow strip of land that jets out into theAtlantic, and so ... so, many houses in this particular style were built on CapeCod, that the name of the place became the name of the style.Now why did the Cape Cod style house become so popular in the northeast?Well, one reason is that it’s a great example of form following function. We’vetalked about this design principle a lot about form following function. And whatdid we say it meant? Someone give me an application of this principle. What isthis concept that form should follow function? How would it be applied tohousing design?Student 2：Well, if it means that the design of a building should be basedon the needs of the people who use it. Then, well, the architect has to be verypractical to think about the people who’ll actually be living in the house orworking in the office building, whatever, so for the architect, it’s all aboutthe users not about showing off how creative you can be.Professor：Good, of course, for a Cape Cod house, it might be even moreaccurate to say that form also follows climate. Who knowswhat the climate’slike on Cape Cod?Student 1：Cold in the winter…Student 2：And whenever I visit my grandparents, it’s really wet. It’susually either raining or snowing or foggy and windy, too. I guess because it’sso exposed to the ocean?Professor：That’s right. So take an other look at this drawing, and you can imagine how this design might be particularly helpful in that kind of climate. Notice how the house sits fairly low to the ground. This relatively low compact structure helps the house withstand the strong winds blowing off the ocean. And look at the：slope of the roof, the steep angle helps keep off all that rain and snow that accumulates in the winter.Another thing, Cape Cod houses usually face south to take advantage of the sun’s warm through the windows. That’s helpful in winter.Now what can you tell me about the chimney, about its location?Student 2：Well, it’s in the middle. Because, does that have something to do with heating the houses? I mean since the heat never has to travel very far. Student 1：That’d mean you can heat the house more efficiently, right? Professor：Exactly, now see how the house has very little exterior decoration, that’s also typical of early Cape Cod houses. The wind was one reason, nothing sticking out that might blow away in the harsh weather, but there was probably another reason, not related to the climate, more a reflection of rural New England society back then, you see Cape Cod houses were not built in the big cities, where all therich people lived back then. These were modest dwellings, the people who built them simply couldn’t afford lots of expensive decorative details. But it was more than just a matter of money. In these rural areas, people depended on each other for survival. Neighbors had to help andsupport each other in a diff icult environment, so you didn’t want to appear to be showing off. You’d want to avoid anything that might set you apart from your neighbors, the same people you might need to help you someday. So all these help to create an attitude of conformity in the community, and you can see why a modest, a very plain style would have become so widely imitated throughout rural New England.Student 2：It is plain, but you know its nice looking.Professor：Good point, and in fact it’s precisely that aesthetic appeal, the…the purity, the nearly perfect proportions of the house…that’s another reason for the Cape Cod’s enduring popularity, even in places where the climate is so mild that its functional design doesn’t matter.希望这些对你的托福备考有帮助，预祝大家托福考试能取得理想成绩。

2019年TPO1托福听力Lecture2原文文本TPO1托福听力Lecture2原文文本Uranium-Lead DatingProfessor: Ok, let’s get started. Great, today I want to talk about a way in which we are able to determine how old a piece of land, or some other geologic feature is - dating techniques. I’m going to talk about a particular dating technique. Why? Good dating is a key to good analysis. In other words, if you want to know how a land formation was formed, the first thing you probably want to know is how old it is. It’s fundamental.Um…Take the Grand Canyon for instance. Now, we geologists thought we had a pretty good idea of how the Grand Canyon in the southwestern United States was formed. We knew that it was formed from sandstone that solidified somewhere between 150 and 300 million years ago. Before it solidified, it was just regular sand. Essentially, it was part of a vast desert.And until just recently, most of us thought the sand had come from an ancient mountain range fairly close by that flattened out over time. That’s been the conventional wisdom among geologists for quite some time. But now we’ve learned something different, and quite surprising, using a technique called Uranium-Lead Dating.I should say that Uranium-Lead Dating has been around for quite awhile. But there have been some recent refinements. I will get into this in a minute. Anyway, Uranium-Lead Dating has produced some surprises. Two geologists discovered that about half of the sand from the Grand Canyon was actually once part of the Appalachian Mountains. That’s really eye-opening news, since the Appalachian Mountain Range is, of course, thousands of kilometers to the east of the Grand Canyon. Sounds pretty unbelievable, right?Of course, the obvious question is how did that sand end up so far west? The theory is that huge rivers and wind carried the sand west where it mixed in with the sand that was already there. Well, this was a pretty revolutionary finding. Um…and it was basically because of Uranium-Lead Dating. Why?Well, as everyone in this class should know, we usually look at the grain type within sandstone, meaning the actual particles in the sandstone, to determine where it came from. You can do other things too, like look at the wind or water that brought the grains to their location and figure out which way it was flowing. But that’s only useful up to a point, and that’s not what these two geologists did.Uranium-Lead Dating allowed them to go about it in an entirely different way. What they did was: they looked at the grains of Zircon in the sandstone. Zircon is a material that contains radioactive Uranium, which makes it very useful for dating purposes.Zircon starts off as molten magma, the hot lava from volcanoes. This magma then crystallizes. And when Zircon crystallizes, the Uranium inside it begins to change into Lead. So if you measure the amount of Lead in the Zircon grain, you can figure out when the grain was formed. After that, you can determine the age of Zircon from different mountain ranges.Once you do that, you can compare the age of the Zircon in the sandstone in your sample to the age of the Zircon in the mountains. If the age of the Zircon matches the age of one of your mountain ranges, then it means the sandstone actually used to be part of that particular mountain range. Is everybody with me on that? Good, so, in this case, Uranium-Lead Dating was used to establish that half of the sandstone in the samples was formed at the same time the granite in the Appalachian Mountains was formed.So because of this, this new way of doing Uranium-Lead Dating, we’ve been able to determine that one of our major assumptions about the Grand Canyon was wrong. Like I said before, Uranium-Lead Dating has been with us for a while. But, um…until recently, in order to do it, you really had to study many individual grains. And it took a long time before you got results. It just wasn’t very efficient. And it wasn’t very accurate.But technical advances have cut down on the number of grains you have to study, so you get your results faster. So I’ll predict thatUranium-Lead Dating is going to become an increasingly popular dating method. There are a few pretty exciting possibilities for Uranium-Lead Dating.Here is one that comes to mind. You know the theory that earth’s continents were once joined together and only split apart relatively recently? Well, with Uranium-Lead Dating, we could prove that more conclusively. If they show evidence of once having been joined, that could really tell us a lot about the early history of the planet’s geology.1.What does the professor mainly discuss?a) The difference in age among American mountain rangesb) The importance of a technique used for dating geological materialsc) The recent discovery of an ancient canyond) A comparison of various minerals used for dating2.Before the use of uranium-lead analysis, where did most geologists think the Grand Canyon sandstone came from?a) An ancient lake located in the American Southwestb) A desert that once connected two continentsc) Sands carried by a river from the Appalachian Mountainsd) A nearby mountain range that had flattened out over time3.Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting theTHREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.In the talk, the professor describes the sequence of uranium-lead dating.Summarize the sequence by putting the events in the correct order.Answer Choicesa) Zircon in the sandstone is matched to the zircon in a particular mountain range.b) The amount of lead in sandstone zircon is measured.c) The age of zircon in a sandstone sample is determined.4.According to the professor, what change has caused uranium-lead dating to gain popularity recently?a) It can be performed outside a laboratory.b) It can now be done more efficiently.c) It no longer involves radioactive elements.d) It can be used in fields other than geology.5.Why does the professor talk about the breaking apart of Earth's continents?a) To give another example of how uranium-lead dating might be usefulb) To explain how the Grand Canyon was formedc) To demonstrate how difficult uranium-lead dating isd) To disprove a theory about the age of Earth's first mountain ranges6.What does the professor imply when he says this?a) The class is easier than other geology classesb) The class has already studied the information he is discussingc) Some students should take a course in geological dating techniquesd) He will discuss the topic later in the class第1题：正确答案：B 主旨题对应原文：0'8"-0'36"Today I want to talk about a way in which we are able to determine how old a piece of land, or some other geologic feature is - dating techniques. I’m going to talk about a particular dating technique. Why? Good dating is a key to good analysis. In other words, if you want to know how a land formation was formed, the first thing you probably want to know is how old it is. It’s fundamental.解析：这篇讲座的主题是年代测定技术。

托福听力tpo61lecture1、2、3原文+题目+答案+译文Lecture1 (1)原文 (1)题目 (3)答案 (5)译文 (5)Lecture2 (7)原文 (7)题目 (9)答案 (11)译文 (11)Lecture3 (13)原文 (13)题目 (15)答案 (17)译文 (17)Lecture1原文Listen to part of a lecture in a sociology class.Sociology is really a cross disciplinary field.We find that elements of biology, psychology,and other sciences often overlap as we study particular phenomena.So let me introduce a concept from cognitive psychology.Okay,let's say someone asks you to look at a list and memorize as many items on it as you can.Most of us are able to remember,on average,seven items.There are several variations of this memory test.And the results consistently show that the human limit for short term memoryis seven bits of Information.This limit is called channel capacity.Channel capacity is the amount of information that can be transmitted or received over a specific connection,like our brain and the channel capacity for our short-term memory.It has some interesting real-life implications,like phone numbers.Local numbers here in the United States all have seven digits,because the phone companies realized early on that longer numbers would lead to a lot more wrong numbers being dialed.But the idea of channel capacity doesn't apply just to our cognitive abilities.It also affects our relationships with people around us.Psychologists talk about sympathy groups.These are the people,close friends,family to whom we devote the most time.We call or see them frequently,we think about them,worry about them.And studies show for each of us,the size of that group is about10to15people.But why so small?sure.Relationships take time and emotional energy.And most of us don't have unlimited amounts of either.But what if there's another reason?what if it's our brain that setting the limit?And in fact,there's evidence that indicates that our social channel capacity may actually be a function of our brain size,or more accurately,the size of our neocortex.The neocortex is the frontal region in the brain of mammals that's associated with complex thought.Primates have the largest neocortex is among mammals,but among different primate species,humans,apes,baboons, neocortex size varies.A lot of theories have been proposed for these variations.Like maybe it's related to the use of tools,but no theories ever seemed like a perfect explanation.Until the late1990s,what an anthropologist named Robin Dunbar published an article about his studies of primates.Dunbar theory is that if you look at any particular species of primate,you'll find that if it has a larger neocortex that it lives in a larger social group.Take human beings,we have the largest neocortices and we have the largest number of social relationships.So we've said that our sympathy group is10to15people.What about our other relationships other than family and close friends,such as those that occur in the workplace will call these social groups as opposed to sympathy groups?How many relationships can we handle there?Those relationships aren't as involved,so we can handle more of them.But is there an upper limit?well,Dunbar says that there is,and he developed an equation to calculate it.His equation depends on knowing the ratio between the size of the neocortex and the size of the whole brain.That is of the whole brain,what percentage of it is taken up by the neocortex?Once you know the average percentage for any particular species,the equation predicts the expected maximum social group size for that species.For humans,that number seems to be about150. So according to Dunbar’s equation,our social groups probably won't number more than150people.Now,Dunbar’s hypothesis isn't the kind of thing that's easy to confirm in a controlled experiment,but there is anecdotal evidence to support it.As part of his research,Dunbar reviewed historical records for21different traditional hunter gatherer societies.And those records showed that the average number of people in each village was just under150,148.4to be exact.Dunbar also worked with biologists to see if his hypothesis applies to other mammals besides primates. When they looked at meat eating mammals,carnivores,they found that the ones with a larger neocortex also have a bigger social group.And the number of individuals in that group is predicted by Dunbar’s equation supporting his hypothesis. But when they looked at insectivores,mammals that eat insects,the results were inconsistent.The data didn't disprove Dunbar’s hypothesis,but wasn't a nice,neat match like the carnivore studies,which isn't totally surprising.Insectivores are hard to observe,since many of them only come out at night or they spend a lot of time underground.So,we know a lot less about their social relationships.题目1.What is the lecture mainly about?A.The role that the neocortex plays in human memoryB.The connection between neocortex size and social relationships in mammalsC.Various studies that compare social group sizes in humans and other mammalsD.Ways that humans can expand the size of their social groups2.Why does the professor discuss the length of some telephone numbers?A.To show that real-world applications are informed by cognitive psychologyB.To point out an exception to a well-known principle about memoryC.To explain why telephone numbers are used in tests of memoryD.To explain why people often dial the wrong telephone number3.What does the professor imply about the size of a person's sympathy group?A.It closely matches the size of the person's family.B.It becomes larger when a person learns how to feel compassion for others.C.It may not be something a person makes a conscious decision to control.D.It may not be as predictable as the size of the person's social group.4.What did Dunbar's study of the records of some traditional hunter-gatherer societies indicate?A.Hunter-gatherer societies were the first to form social groups.B.Tool usage by humans is related to social group size.C.There is a maximum social group size for humans.D.Hunter-gatherers tend to have smaller-sized social groups.5.What does the professor say that biologists discovered in their research of animals other than primates?A.Dunbar's hypothesis accurately predicts social group sizes for all animals.B.Social group sizes of carnivores are more difficult to predict than those of insectivores.C.Data on insectivore behavior neither support nor contradict Dunbar's hypothesis.D.The size of an animal's neocortex is affected by its diet.6.Why does the professor say this:But why so small?sure.Relationships take time and emotional energy.And most of us don't have unlimited amounts of either.A.To encourage students to spend more time developing relationshipsB.To emphasize that her point is based on personal experienceC.To indicate that she realizes that the students already know the answer to her questionD.To suggest that there is more than one possible response to her question答案B AC C C D译文请听社会学课上的部分内容。