TPO，即TOEFL Practice Online的首写字母，就是托福在线练习的意思。由于托福是机考模式，所以ETS提供了26套(当前数字)TPO供考生们使用，为考生提供全真的模拟考试环境和过往真题。考生可以用它来感受和体验真实的托福考试题型，熟悉操作界面和平台，检验自己的复习效果。
Listen to a conversation between two students.
(man) Hey, Beth, how are things?
(woman) Not great.
(man) Why? What’s wrong?
(woman) I just found out I have to move out of my apartment, like, right away.
(man) You’re kidding! Why?
(woman) Well, my apartment, it’s in a house, a kind of old house. And now something’s wrong with the water pipes. I think some of the pipes burst or wore out or something. Anyway, we don’t have any water in the house, and apparently it’s gonna take two weeks to fix the problem.
(man) So you need to find a place to live for what? two weeks or so?
(woman) Yeah, bad timing, huh? With mid-term exams coming up and everything!
(man) So you’ve figured out what you’re going to do?
(woman) Well, some friends said I could stay at their place. They don’t have an extra bedroom but they said it’d be OK for me to sleep on their living room couch.
(man) You could probably handle that for a couple of weeks, right?
(woman) I guess so. I mean it’s really nice of them to offer. And it’s free! The only problem is they already have four people living there so it could be a little crowded. (man) And not ideal for studying for mid-terms.
(woman) Yeah, too many distractions.
(man) Hmmm, any other options?
(woman) Well, I did find this place. It’s a small hotel over on 3rd street right near campus.
(man) Oh, right! A lot of kid’s parents stay there when they come for a visit.
(woman) Right. So I could get a room there. They have a weekly rate and it’s pretty reasonable. But, I don’t know..
(man) At least at the hotel you’d have a space of your own, you know, so you could get more done.
(woman) That’s definitely a plus. But I have to think about it. Even though it’s pretty cheap, it’ll still end up costing me some money. And my budget is pretty tight right now.
Briefly summarize the problem the speakers are discussing. Then state which solution you would recommend. Explain the reasons for your recommendation.
The woman has to move out of her apartment right away because there is something wrong with the water pipe and it’s going to take about two weeks to fix it. Also, the mid-term exams are coming up. The first solution is to stay at some friends’ place. The woman can sleep on the living room couch. But their place has already got four people, it’ll be a little crowded. Plus, there will be many distractions. The second solution is live in a hotel near campus. She could get a room there. But her budget is very tight now, even if the weekly rate is reasonable, it’ll still end up costing her some money. Considering the options and problems, I would recommend her to choose the first solution. Since her budget is tight, living at the friends’ place can save her money. Concerning the problem of distractions, she can just study in classrooms and only sleep on the couch at night.
Listen to a conversation between a student and a counselor at the University
Hi, thanks for seeing me in such short notice.
No problem. How can I help?
Well, I think I might have made a mistake coming to the school.
What makes you say that?
I’m a little overwhelmed by the size of this place. I come from a small town. There were only 75 of us in my high school graduating class. Everyone knew everyone. We all grew up together.
So it’s a bit of a culture shock for you? Being one of 15,000 students on a big campus in an unfamiliar city?
That’s an understatement. I just can’t get comfortable in class or in the dorms. You know, socially.
Um…well, let’s start with the academics. Tell me about you classes.
I’m taking mostly introductory courses and some are taught in these huge lecture halls.
And you are having trouble in keeping pace with the material?
No, in fact I got an A on my first economics paper. It’s just that, it’s so impersonal, I’m not used to it.
Are your classes impersonal?
No, it’s just that…for example, in sociology yesterday, the professor asked a question, so I raised my hand, several of us raised our hands. And I kept my hand up because I did the reading and knew the answer. But the professor just answered his own question and continued with the lecture.
Well, in a big room it’s possible he didn’t notice you. Maybe he was starting to save time. In either case I wouldn’t take it personally.
I suppose. But I just don’t know how to, you know, distinguish myself.
Why not stop by his office during office hours?
That wouldn’t seem right. You know, taking time from other students who need help?
Don’t say that. That’s what office hours are for. There is no reason you couldn’t pop in to say hi and to make yourself known. If you are learning a lot in class, let the professor know. Wouldn’t you appreciate positive feedback if you were a professor?
You are right. That’s a good idea.
OK, er…let’s turn to your social life. How’s it going in the dorms?
I don’t have much in common with my roommate or anyone else I’ve met so far. Everyone’s into sports and I’m more artsy, you know, into music. I play the cello.
Hah, have you been playing long?
Since age ten. It’s a big part of my life. At home I was the youngest member of our community orchestra.
You are not going to believe this. There is a string quartet on campus, all students. And it so happened that the cellist graduated last year. They’ve been searching high and low for a replacement, someone with experience. Would you be interested in auditioning?
Absolutely. I wanted to get my academic work settled before pursuing my music here. But I think this would be a good thing for me. I guess if I really want to fit in here I should find people who love music as much as I do. Thank you.
Listen to part of a lecture in a sociology class.
Have you ever heard the one about alligators living in New York sewers? The story goes like this: a family went on vacation in Florida and bought a couple of baby alligators as presents for their children, then returned from vacation to New York, bringing the alligators home with them as pets. But the alligators would escape and find their way into the New York sewer system where they started reproducing, grew to huge sizes and now strike fear into sewer workers. Have you heard this story? Well, it isn’t true and it never happened. But despite that, the story has been around since the 1930s. Or how about the song ‘twinkle, twinkle little star’, you know, ‘twinkle, twinkle, little star, how I wonder what you are’. Well we’ve all heard this song. Where am I going with this? Well, both the song and the story are examples of memes. And that’s what we would talk about, the theory of memes. A meme is defined as a piece of information copied from person to person. By this definition, most of what you know, ideas, skills, stories, songs are memes. All the words you know, all the scientific theories you’ve learned, the rules your parents taught you to observe, all are memes that have been passed on from person to person. So what? You may say. Passing on ideas from one person to another is nothing new. Well, the whole point of defining this familiar process as transmission of memes is so that we can explore its analogy with the transmission of genes. As you know, all living organisms pass on biological information through the genes. What’s a gene? A gene is a piece of biological information that gets copied or replicated, and the copy or replica is passed on to the new generation. So genes are defined as replicators. Genes are replicators that pass on information about properties and characteristics of organisms. By analogy, memes also get replicated and in the process pass on culture information from person to person, generation to generation. So memes are also replicators. To be a successful replicator, there are three key characteristics: longevity, fecundity and fidelity. Let’s take a closer look. First, longevity. A replicator must exist long enough to be able to get copied, and transfer its information. Clearly, the longer a replicator survives, the better its chances of getting its message copied and passed on. So longevity is a key characteristic of a replicator. If you take the alligator story, it can exist for a long time in individual memory, let’s say, my memory. I can tell you the story now or ten years from now, the same with the twinkle, twinkle song. So these memes have longevity because they are memorable for one reason or another. Next, fecundity. Fecundity is the ability to reproduce in large numbers. For example, the common housefly reproduces by laying several thousand eggs, so each fly gene gets copied thousands of times. Memes, well, they can be reproduced in large numbers as well. How many times have you sung the ‘twinkle, twinkle song’ to someone? Each time you replicated that song, and maybe passed it along to someone who did not know it yet, a small child maybe. And finally, fidelity. Fidelity means accuracy of the copying process. We know fidelity is an essential principle of genetic transmission. If a copy of a gene is a bit different from the original, that’s called a genetic mutation. And mutations are usually bad news. An organism often can not survive with a mutated gene. And so a gene usually can not be passed on, unless it’s an exact copy. For memes however, fidelity is not always so important. For example, if you tell someone the alligator story I told you today, it probably won’t be word for word exactly as I said it. Still, it will be basically the same story, and the person who hears the story will be able to pass it along. Other memes are replicated with higher fidelity though, like the twinkle, twinkle song. It had the exact same words 20 years ago as it does now. Well, that’s because we see songs as something that has to be performed accurately each time. If you change a word, the others will usually bring you in line. They’ll say, ‘that’s not how you sing it’, right? So, you can see how looking at pieces of cultural information as replicators, as memes, and analyzing them in terms of longevity, fecundity and fidelity, we can gain some inside about how they spread, persist or change
Listen to part of a lecture in an Astronomy Class
Last week, we covered some arguments against going back to the Moon. But there are compelling reasons in favor of another Moon landing too, um… not the least of which is trying to pinpoint the moon’s age. We could do this in theory by studying an enormous impact crater, known as the South Pole-Aitken Basin. Um…it’s located in the moon’s South Polar Region. But, since it’s on the far side of the moon, it can only be seen from space. Here is an image of…we’ll call it the SPA Basin. This color-coated image of the SPA Basin, those aren’t its actual colors obviously, this image is from the mid 90s, from the American spacecraft called Clementine. Um… unlike earlier lunar missions, Clementine didn’t orbit only around the moon’s equator. Its orbits enable it to send back data to create this topographical map of … well, the grey and white area towards the bottom is the South Pole, the purples and blues in the middle correspond to low elevations - the SPA Basin itself, the oranges and reds around it are higher elevations. The basin measures an amazing 2,500 km in diameter, and its average depth is 12 km. That makes it the biggest known crater in our solar system and it may well be the oldest. You know planetary researchers love studying deep craters until learn about the impacts that created them, how they redistributed pieces of a planet’s crust and in this case, we especially want to know if any of the mantle, the layer beneath the crust, was exposed by the impact. Not everyone agrees, but some experts are convinced that whatever created the SPA Basin did penetrate the Moon’s mantle. And we need to find out, because much more than the crust, the mantle contains information about a planet’s or Moon’s total composition. And that’s key to understanding planet formation. Um… Dian? Dian: So, the only way to know the basin’s age is to study its rocks directly? Professor: well, from radio survey data, we know that the basin contains lots of smaller craters. So it must be really old, about 4 billion years, give or take a few hundred million years. But that’s not very precise. If we had rock samples to study, we’d know whether the small craters were formed by impacts during the final stages of planetary formation, or if they resulted from later meteor showers. Dian: But if we know around how old the Basin is, I’m not sure that’s reason enough to go to the Moon again. Professor: No…, but such crude estimates…um…we can do better than that. Besides, there are other things worth investigating, like is there water ice on the moon? Clementine’s data indicated that the wall of the south-polar crater was more reflective than expected. So some experts think there’s probably ice there. Also, data from a later mission indicates significant concentrations of hydrogen and by inference water less than a meter underground at both poles. Student: Well if there’s water, how did it get there? Underground rivers? Professor: We think meteors that crashed into the moon or tails of passing comets may have introduced water molecules. Any water molecules that found their way to the floors of craters near the moon’s poles, that water would be perpetually frozen, because the floors of those craters are always in shadow. Um…furthermore, if the water ice was mixed in with rock and dust, it would be protected from evaporation. Dian: So are you saying there might be primitive life on the moon? Professor: that’s not my point at all. Um… o.k., say there is water ice on the moon. That would be a very practical value for a future moon base for
astronauts. Water ice could be melted and purified for drinking. It could also be broken down into its component parts - oxygen and hydrogen. Oxygen could be used to breathe, and hydrogen could be turned into fuel, rocket fuel. So water ice could enable the creation of a self-sustaining moon base someday, a mining camp perhaps or a departure point for further space exploration. Student: But holding tons of equipment to the moon to make fuel and build a life support system for a moon base, wouldn’t that be too expensive? Professor: Permanent base, maybe a way’s off, but we shouldn’t have to wait for that. The dust at the bottom of the SPA Basin really does have a fascinating story to tell. I wouldn’t give for a few samples of it.
Listen to a conversation between a student and a professor.
Hi, I was wondering if I could talk with you about the assignment in the film theory class.
Of course, Jill.
It seems that pretty much everyone else in the class gets what they are supposed to be doing but I’m not so sure.
Well, the class is for students who are really serious about film. You must have taken film courses before.
Yeah, in high school, film appreciation.
Um…I wouldn’t think that would be enough. Did you concentrate mainly on form or content?
Oh, definitely content. We’d watch, say Lord of the Flies, and then discuss it.
Oh, that approach, treating film as literature, ignoring what makes it unique.
I liked it, though.
Sure, but that kind of class. Well, I’m not surprised that you are feeling a little lost. You know, we have two introductory courses that are supposed to be taken before you get to my course, one in film art, techniques, technical stuff and another in film history. So students in the class you are in should be pretty far along in film studies. In fact, usually the system blocks anyone trying to sign up for the class they shouldn’t be taking. And who hasn’t taken the courses you are required to do first as prerequisites.
Well, I did have a problem with that but I discussed it with one of your office staff, and she gave me permission.
Of course. No matter how many times I tell them, they just keep on… Well, for your own good, I really suggest dropping back and starting at the usual place.
Yes. But I’ve already been in this class for 4 weeks. I’d hate to just drop it now especially since I find it so different, so interesting.
I guess so. Frankly I can’t believe you’ve lasted this long. These are pretty in-depth theories we’ve been discussing and you’ve been doing OK so far, I guess. But still, the program’s been designed to progress through certain stages. Like any other professional training we build on pervious knowledge.
Then maybe you could recommend some extra reading I can do to… catch up?
Well, are you intending to study film as your main concentration?
No, no. I am just interested. I’m actually in marketing, but there seems to be a connection.
Oh…well, in…in that case, if you’re taking the course just out of interest, I mean I still highly recommend signing up for the introductory courses at some point, but in the meantime, there is no harm I guess in trying to keep up with this class. The interest is clearly there. Eh, instead of any extra reading just now though, you could view some of the old introductory lectures. We have them on video. That would give you a better handle on the subject. It’s still a pretty tall order, and we will be moving right along, so you will really need to stay on top of it.
OK, I’ve been warned. Now, could I tell you about the idea for the assignment?
Listen to part of a lecture in a chemistry class.
Okay. I know you all have a lot of questions about this lab assignment that's coming out so ... I'm gonna take a little time this morning to discuss it.
So, you know the assignment has to do with Spectroscopy, right? And your reading should help you get a good idea of what that's all about. But, let's talk about Spectroscopy a little now just to cover the basics. What is Spectroscopy? Well, the simplest definition I can give you is that Spectroscopy is the study of the interaction between matter and light. Now, visible light consists of different colors or wavelengths, which together make up what's called spectrum, a band of colors, like you see in a rainbow. And all substances, all forms of matter, can be distinguished according to what wavelength of light they absorb and which ones they reflect. It's like, um, well, every element has, what we call, its own spectral signature. If we can read that signature, we can identify the element. And that's exactly what spectroscopy does.
Now, Laser Spectroscopy, which is the focus of your assignment, works by measuring very precisely what parts of the spectrum are absorbed by different substances. And it has applications in a lot of different disciplines. And your assignment will be to choose a discipline that interests you, and devise an experiment. For example, I'm gonna talk about art. I'm interested in the art and to me it's interesting how spectroscopy is used to analyze art. Er... let's say a museum curator comes to you with a problem. She's come across this painting that appears to be an original - let's say, a Rembrandt. And she wants to acquire it for her museum. But she's got a problem: she's not absolutely certain it's an original. So, what do you do? How do you determine whether the painting's authentic? Okay. Think about the scientific process. You've got the question: Is the painting a Rembrandt? So first, you'll need to make a list of characteristics the painting would have to have to be a Rembrandt. Then you have to discover whether the painting in question has those characteristics. So first of all, you’ll need to know the techniques Rembrandt used when he applied paint to canvas - his brushstrokes, how thickly he applied his paint. So you’d need to work with an art historian who has expert knowledge of Rembrandt's style. You'd have to know when he created his paintings, um... what pigments he used, in other words, what ingredients he used to make different colors of paint, cost the ingredients used in paints and binding agents plus varnishes, finishes, what have you, have changed over time. Since you're trying to verify that's a Rembrandt, the ingredients in the pigment would need to have been used during Rembrandt's lifetime - in the 17th century. And that's where chemistry comes in. You've got to find out what's in those pigments, learn their composition, and that requires lab work – detective work really - in a word, Spectroscopy. So, how do we use Spectroscopy? Well, we put an infrared microscope – a spectroscope - on tiny tiny bits of paint. And using ultraviolet light we can see the spectral signature of each component part of the pigment. Then we compare these signatures with those of particular elements like zinc or lead, to determine what the pigment was made of. So, you can see why this type of analysis requires a knowledge of the history of pigments, right? How and when they were made? Say we determined a pigment was made with zinc, for example. We know the spectral signature of zinc. And it matches that of the paint sample. We also know that zinc wasn't discovered until the 18th century. And since Rembrandt lived during the 17th century, we know he couldn't have painted it. Now, Spectroscopy has a very distinct advantage over previous methods of analyzing our works, because it's not invasive. You don't have to remove big chips of paint to do your analysis, which is what other methods require. All you do is train the microscope on tiny flecks of paint and analyze them. Now a word or two about restoration. Sometimes original art works appear questionable or inauthentic because they’ve had so many restorers add touchup layers to cover up damage, damage from the paint having deteriorated over time. Well, spectroscopy can review the composition of those touchup layers too. So we can find out when they were applied. Then if we want to undo some bad restoration attempts, we can determine what kind of process we can use to remove them to dissolve the paint and uncover the original.
Listen to part of a lecture in a literature class.
Now we can't really talk about fairy tales without first talking about folk tales because there's a strong connection between these two genres, these two types of stories. In fact, many fairy tales started out as folk tales. So, what's a folk tale? How would you characterize them? Jeff?
Well, they are old stories, traditional stories. They were passed down orally within cultures from generation to generation, so they changed a lot over time. I mean, every story teller, or, maybe every town, might have had a slightly different version of the same folk tale.
That's right. There's local difference. And that's why we say folk tales are communal. By communal, we mean they reflect the traits and the concerns of a particular community at a particular time. So essentially the same tale could be told in different communities, with certain aspects of the tale adapted to fit the specific community. Um, not the plot, the details of what happens in the story would remain constant. That was the thread that held the tale together. But all the other elements, like the location or characters, might be modified for each audience. Okay. So what about fairy tales? Th…they also are found in most cultures, but how are they different from folk tales? I guess the first question is: what is a fairy tale? And don’t anyone say “a story with a fairy in it” because we all know that very few fairy tales actually have those tiny magical creatures in them. But, what else can we say about them? Mary.
Well, they seem to be less realistic than folk tales…like they have something improbable happening a frog turning into a prince, say. Oh, that's another common element, royalty - a prince or princess. And fairy tales all seem to take place in a location that's nowhere and everywhere at the same time.
What's the line-up? How do all the stories start? Once upon a time, in a far away land... oh, in the case of folk tales, each story teller would specify a particular location and time, though the time and location would differ for different story tellers. With fairy tales, however, the location is generally unspecified, no matter who the story teller is. That land far away... We'll come back to this point in a few minutes.
Um... I, I thought that a fairy tale was just a written version of an oral folk tale.
Well, not exactly, though that is how many fairy tales developed. For example, in the late 18th century, the Grimm Brothers traveled throughout what's now Germany, recording local folk tales. These were eventually published as fairy tales, but not before undergoing a process of evolution. Now, a number of things happen when an oral tale gets written down. First, the language changes. It becomes more formal, more standard - some might say, "less colorful". It's like the difference in your language depending on whether you are talking to someone, or writing them a letter. Second, when an orally transmitted story is written down, an authoritative version with a recognized author is created. The communal aspect gets lost. The tale no longer belongs to the community. It belongs to the world, so to speak. Because of this, elements like place and time can no longer be tailored to suit a particular audience. So they become less identifiable, more generalizable to any audience. On the other hand, descriptions of characters and settings can be developed more completely. In folk tales, characters might be identified by a name, but you wouldn't know anything more about them. But in fairy tales, people no longer have to remember plots. They're written down, right? So more energy can be put into other elements of the story like character and setting. So you get more details about the characters, about where the action takes place, what people's houses were like, ur, whether they're small cabins or grand palaces. And it's worth investing that energy because the story, now in book form, isn't in danger of being lost. Those details won't be forgotten. If a folk tale isn't repeated by each generation, it may be lost for all time. But with a fairy tale, it's always there in a book, waiting to be discovered, again and again. Another interesting difference involves the change in audience. Who the stories are meant for? Contrary to what many people believe today, folk tales were originally intended for adults, not for children. So why is it that fairy tales seem targeted toward children nowadays?
trol what they create. In other words, the arguments both for and against government funding of the arts are as many and, and as varied as the individual styles of the artists who hold them.