Tuesday, October 8, 2013

TOEFL LISTENING lecture enviromental class 托福听力听写练习

original listening material is from toefl listeing test.
Red marked places are mistakes I made when recording it.

Listen to part of a lecture in an environmental science class.

Now, we’ve been talking about the loss of animal habitat from housing developments, uh…, growing cities - small habitat lossss. But, today I wanna begin talking about what happens when habitat is reduced across a large area. There are, of course, animal spices that require large areas of habitat, and some migrate over very long distances. So what’s the impact of habitat loss on those animals – animals that need large areas of habitat. Well, I’ll use humming birds as an example. Now, you know that a humming bird is small, but even though it’s really tiny, it migrates over a very long distances, travel ups and down the western hemisphere - the Americas, back and forth between where it breeds in the summer and the warmer climates where it’s spent the winter.

So you would say that the whole area over which it migrates is its habitat because on this long distance journey, it needs to come down to feed and sleep every so often, right? Well, the humming bird beats its wings - get this - about 3000 times per minute. So you might think, wow, it must need a lot of energy, a lot of food, right?

Well, it does. It drinks a lot of nectar from flowers and feeds on some insects. But it’s energy-efficient too. You can’t say it isn’t. I mean, as it flies all the way across the Mexico Gulf, it uses up none of its body fat. But that doesn’t mean it doesn’t need to eat. So humming birds have to rely on the plants in their natural habitat.

And it goes without saying, but the opposite is true as well, plants depend on ha too. There are some flowers only that can only be pollinated by the humming birds. With its stopping to feed and spread pollen from flower to flower, these plants would cease to exist.

But the problem… well, as natural habitat along these migration routes is developed by humans for housing or agriculture or cleared for raising cattle, for instance, there is less food available for migrating humming birds. Their nesting sites are affected by the same sorts of human activities. And all of these human activities pose a real threat to the humming bird population.

So help them survive, we need to preserve their habitats. And one of the concrete ways people have been doing this is by cleaning up polluted habitat areas and then replanting flowers, um, replanting native flowers that humming birds feed on.

Promoting ecological tourism is another way to help save their habitat. As the number of visitors, eco-tourists who come to humming bird habitats to watch the birds, the more the number of visitors grows, the more local businesses’ profit. So ecological tourism can bring them financial rewards, all the more reason to value all this beautiful little creatures in their habitat, right?

But to understand more about how to protect them to support the humming birds the best we can, we’ve got to learn more about their breeding, nesting sites and migration routes, and also about the natural habitats we find there. That just helps us to determine how to prevent further decline in the population.

A good research method, a good way to learn more, is by running a banding study. Banding the birds allows us to track them over their lifetime. It’s been a practice that’s been used by researchers for years. In fact, most of what we’ve known about humming birds comes from binding studies, where we capture a humming bird and make sure all the information about it, like its weight and age and length, are all recorded and put into an international information database.

And then we place an extremely lightweight band on one of its leg, well, what looks like a leg, although technically it’s considered part of the bird’s foot. Anyway, these bands are perfectly safe, and some humming birds have worn them for years with no evidence of any problems. The band is labeled with tracking number, oh, and there is a phone number on the band for people to call for free, to report a banded bird to be found or recaptured.

So when a banded bird is recaptured and reported, we learn about its migration route, its growth, and how long it has been alive, its lifespan. One recaptured bird was banded almost 12 years earlier – she was one of the oldest humming birds on record. Another interesting things we learned is that humming birds no longer use a certain route. They travel by a different route to reach their destinations. And findings like these have been of interest to biologists and environmental scientists in a number of countries who are trying to understand the complexities of how changes in a habitat affect the species in it.

Monday, September 30, 2013

TOEFL LISTENING CONVERSATION 托福听力听写练习 对话

Original listening material is from TOEFL listening test.
Red marked parts are mistakes I made when recording it.

Listen to a conversation between a student and a professor.

Uh, Professor Thompson, I know that your office hours are tomorrow, but I was wondering if you had a few minutes free now to discuss something?

 Sure, John. What did you want to talk about?

Well, I have some quick questions about how to write up the research I did this semester - about climate variations?

Oh, yes. You were looking at variations in climate in the Grant City area, right? How far along have you gotten?

I’ve got all my data, so I’m starting to summarize it now, preparing graphs and stuff. But, I’m just … I’m looking at it and I’m afraid that it’s not enough, but I’m not sure what else to put in the report.

I hear the same thing from every student. You know, you have to remember now that you are the expert on what you’ve done. So, think about what you’d need to include if you were going to explain your research to someone with general or casual knowledge about the subject, like … like your parents. That’s usually my rule of thumb: would my parents understand this?

Okay, I get it.

I hope you can recognize by my saying that how much do you know about the subject?

Right. I understand. I was wondering if I should also include the notes from the research journal you suggested I should keep.

Yes, definitely. You should use it to indicate what your revolution in thought was through time. So, just set up, you know what was the purpose of what you were doing - to try to understand the climate variability of this area – and what you did, and what your approach was?

Okay, so, for example, I studied meteorological records, I looked at climate charts; I use different methods for analyzing the data, like certain statistical tests, and then I discuss the results. Is that what you mean?

Yes, that’s right. You should include all of that. The statistical tests are especially important. And also be sure to include a good reference section where all your published and unpublished data came from, ‘cause you have a lot of unpublished climate data.

Hmm, something just came into my mind, and went out of the other side?

That happens to me a lot, so I’ve come up with a pretty good memory management tool. I carry a little pad with me all the time and jot down questions or ideals that I don’t want to forget. For example, I went to the doctor with my daughter and her baby son last week, and we knew that we wouldn’t remember everything we wanted to ask the doctor, so we actually made a list of five things we wanted answers to.

A notepad is a good idea. Since I’m busy now at the end of the semester, I’m getting pretty forgetful these days. OK. I just remembered what I was trying to say before.

Good. I was hoping you’d come up with it.

Yes, it ends up that I have data on more than just the immediate Grant city area, so I also included some regional data in the report, with everything else it should be a pretty good indicator of the climate in this part of the state.

Sounds good. I’d happy to look over a draft version before you hand in the final copy, if you wish?

Great, I’ll plan to get you a draft of the paper by next Friday.Thanks very much. Well, see you.

Okay.

Listen to part of a conversation between a student and a receptionist at the Registrar’s office on the first day of this semester.

Excuse me, I’m supposed to be having my physics class in the science building, but no one’s in the classroom. Could you tell me where the class is? Physics 403 - has it been moved?

Well, there is a room assignment sheet on the bulletin board outside this office.

Yeah, I know, but my class is not listed there. There must be some kind of mistake or something. Could you look it up, please?

Hmmm… okay, let me check on the computer. It’s physics, right? Wait, did you say physics 403?

Yeah.

I’m sorry, but it says here that it was cancelled, but you should have got a note letter from the registrar’s office.

What? I’ve never got it.

Are you sure? ‘cause it says on the computer that the letter was sent out to students a week ago.

Really? I should have got it by now. I wonder if I threw it away with all the junk mail by mistake.

Well, it does happen. Er…, let me check something. What’s your name?

Woodhouse, Laura Woodhouse.

Okay, hmmm… Woodhouse, let me see… ay, it says that we send it to your apartment on er… Center Street.

Oh, that is my old apartment. I moved out of there a little while ago.

Well, and I suppose you haven’t changed your mailing address at the administration office? Well, that would explain it.

Yeah, I guess that’s it. But how can they cancel the class after offering it. If I’d known this was going to happen, I would have taken it last semester.

I know, it’s really inconvenient to you, I understand that, but er… if we don't have enough students sign up for the course, the college can’t offer it. You know, the practical issue, like we can’t have an instructor when there’re only a few students in the class. You see what I mean?

I guess, but now I don’t what course should I take instead.

Okay, let’s see. Do you have any courses you’re going to take next semester? If you do, you might want to take them now and sign up for physics 403 next semester?

Yeah, I guess I can do that. I just hope it won’t be cancelled again. Do you know how many people have to be enrolled in order to keep a class from being cancelled?

Well, it depends on the class, but for that class, you have to have er… let me see, usually it should be at least 10 people. But since it was cancelled this semester, they might even do it with less. But do you know what you should do? Give the physics department a call a couple of weeks before the semester starts. They will be able to tell you if they’re planning to go through it. It’s their decision, actually.

Well, I’ll do that. Thanks for the info!

No problem! Sorry about the class! Oh, why aren’t you to go change a mailing address now? It lonely takes a minute.

Oh, sure, I’ll do that right away.

Tuesday, September 24, 2013

toefl listening material conversation


Listen to a conversation between a student and a professor.

Uh, Professor Thompson, I know that your office hours are tomorrow, but I was wondering if you had a few minutes free now to discuss something?

 Sure, John. What did you want to talk about?

Well, I have some quick questions about how to write up the research I did this semester - about climate variations?

Oh, yes. You were looking at variations in climate in the Grant City area, right? How far along have you gotten?

I’ve got all my data, so I’m starting to summarize it now, preparing graphs and stuff. But, I’m just … I’m looking at it and I’m afraid that it’s not enough, but I’m not sure what else to put in the report.

I hear the same thing from every student. You know, you have to remember now that you are the expert on what you’ve done. So, think about what you’d need to include if you were going to explain your research to someone with general or casual knowledge about the subject, like … like your parents. That’s usually my rule of thumb: would my parents understand this?

Okay, I get it.

I hope you can recognize by my saying that how much do you know about the subject?

Right. I understand. I was wondering if I should also include the notes from the research journal you suggested I should keep.

Yes, definitely. You should use it to indicate what your revolution in thought was through time. So, just set up, you know what was the purpose of what you were doing - to try to understand the climate variability of this area – and what you did, and what your approach was?

Okay, so, for example, I studied meteorological records, I looked at climate charts; I use different methods for analyzing the data, like certain statistical tests, and then I discuss the results. Is that what you mean?

Yes, that’s right. You should include all of that. The statistical tests are especially important. And also be sure to include a good reference section where all your published and unpublished data came from, ‘cause you have a lot of unpublished climate data.

Hmm, something just came into my mind, and went out of the other side?

That happens to me a lot, so I’ve come up with a pretty good memory management tool. I carry a little pad with me all the time and jot down questions or ideals that I don’t want to forget. For example, I went to the doctor with my daughter and her baby son last week, and we knew that we wouldn’t remember everything we wanted to ask the doctor, so we actually made a list of five things we wanted answers to.

A notepad is a good idea. Since I’m busy now at the end of the semester, I’m getting pretty forgetful these days. OK. I just remembered what I was trying to say before.

Good. I was hoping you’d come up with it.

Yes, it ends up that I have data on more than just the immediate Grant city area, so I also included some regional data in the report, with everything else it should be a pretty good indicator of the climate in this part of the state.

Sounds good. I’d happy to look over a draft version before you hand in the final copy, if you wish?

Great, I’ll plan to get you a draft of the paper by next Friday.Thanks very much. Well, see you.

Okay.

Wednesday, September 11, 2013

toefl listening EARTH SCIENCE 托福听力听写练习

Original listeing material is from toefl test.
Redmarked places are the places I made mistakes when recording it.

Earth Science

Listen to part of a lecture in an earth science class. The class is having a discussing.

Okay, so we say rocks of volcanic. What do we really mean? Linda?

Well, would it come out as hot and melts of rock, lava from deep down inside the Earth, and then cool and harden in the air.

Good, except that it isn’t always the air that cools the lava into rock.

Oh, the ocean. Isn’t there a lot of volcanic activity down at the bottom of the ocean? Way out of the middle, along the … oh, what do you call it?

Daniel?

The middle ocean ridge?

Right.

See, how do scientists go about studying that?

Well, in the 70’s, they started mapping the shape of the ocean floor out there with solar. You know how solar works?

Sure, like radar.

Okay.

But solar is sound, high-frequency sound that a ship sends down. Well, the scientists on the ship can tell a lot about the ocean bottom by how these pulses of sounds echo back.

That’s good.

Thanks, but I was wandering like, couldn’t they just go down to the ocean floor in submarines and take a look?

Well, fist, we have to realize that at this depth, say, 3kms down, the pressure will be about 3000 times the pressure up the surface.

Oh, so, you are saying the pressure would crash any submarine out there that tried to go all the way down to the bottom.

Well, for a long time, that was the case, and still is, even today for any normal submarine. But eventually, a few of vey special ones were constructed, with titanium hulks that won’t collapse even at pressures that great. And they have got little windows made of special material that can withstand high pressures, and video cameras and really powerful lights that the people inside the sub use to explore the ocean bottom. And after about 4 hours moving around down there, using a battery-power motor, well, then the submarine releases its weights. The heavy metal weights that put it down. And for the next couple of hours, it’s rising back to the surface, and…

So, what do they end up seeing down there?

Well, for one thing - these long ridges running up and down in the middle of the oceans, they were able to confirm that these were volcanic, not just the origins. But I mean, the hot lava had flowed up recently, sort of like toothpaste coming out of the tube. And it’d cooled into the rock formations along the ridge. Oh, and that reminds me of one dive back in, I think that was 1979. The submarine went down to explore the middle ocean region of Pacific, and I have to understand the temperature of the bottom is normally just about freezing, zero degree celsius. And they’are down there exploring some very new lava formations. And they see what it looks like this big, black, sort of muddy cloud in the water. So they move up close enough to it that they can use this thermometer on the outside of the submarine. And suddenly, it starts melting, this thermometer was made to measure the temperatures over 300 degrees Celsius. It just melts. And these guys realized that temperatures like that can also melt the special windows in their sub. And they’re almost gone right into the middle of this big, black cloud.

Wow.

Yah, you said that - WOW. So, anyway, since then this things have been found spreading up all over along the middle ocean ridges. And now they haven’t a name. We call them smokers - black smokers. And then we’ve came to understand that they are part of a really important process, one that regulates the chemistry of the oceans.  

The chemistry? How so?

Well, we know that the rivers flowing into all the oceans around the world carry dissolved salts. So what happens to those salts? They don’t all just stay dissolved in the water.

No? Then what?

Well, they are cracks in volcanically active parts of the ocean floor where cold ocean water seeps down into the rock below. What do you suppose happens there?

Well, I guess, the water will cool the hot, volcanic rock down there…

And?

And that would heat up the water a lot!

Right, even super-heated, and then shot back again. And in theory, over millions of years, all the water in the oceans could’ve circulated down through the rocky crust, and come back up again super-heated. And in the process, reactions with the hot lava remove the salt, taking them out of water. So when the water shoots up from the ocean floor, it leaves behind the salts, and brings up a hot, thick, and incredibly rich cloud of minerals drawn out of the rock that was cooling.

Those ‘black smoker’ they saw…

Exactly!

Thursday, September 5, 2013

toefl listening astronomy lecture 托福听力听写练习

Original listening material is from toefl test.
Red marked places are the mistakes i made when i recorded it.

Listen to part of a lecture in an astronomy class.

I’m sure you all have been following the news about the Mars. A lot of spacecraft have been visiting the planet recently- some have gone into orbit around it, well, while others have landed on it. And, they’ve sent back a… an abundance of data that’s reshaping our knowledge … our vision of the planet in a lot of ways. Is there anything that you’ve been particularly struck by in all the news reports?

Well, they seem to mention water a lot, which kind of surprised me as I have this picture in my head that Mars is dry… sort of dry and dead.

You are not the only one. You know, for centuries, most of our knowledge of the planet came from what we saw through telescopes. So, obviously, it was pretty limited. And our views of the planet were formed as much by writers… as they were by serious scientists. When the first science-fiction came out, Mars was described as being a lot like Earth except…

I know that the planet was red and, uh, the people are green. I’ve seen some of those old movies. What were they thinking? I mean, reallythey…

Well, it seems silly to us now but those ideas were quite imaginative and, occasionally, scary in their time.  Anyway, we began to rethink our image of Mars when the first spacecraft flew by the planet in 1965 and sent some pictures back to earth. Those pictures showed a planet that looked a lot more like our moon than earth- lots of craters and not much else. It was bitterly code. It had a very thin atmosphere. And that atmosphere was mostly carbon dioxide. So, the view of Mars after this first flyby mission was that dry, dead planet that Lisa mentioned. But then there were more visitors to the planet in the 1970s - and this time the spacecraft didn’t just fly by, they orbited or landed. This allowed us to receive more detailed images of the planet, and it turned out to be a pretty interesting place. Mars hadhas a lot more than craters, it has giant volcanoes and deep canyons. It also showed signs of dried-up riverbeds and plains that had been formed by massive floods. So we can concluded that there must have been water on the planet at one time, billions of years ago. Now, what does it take for water to exist?

You need to have a warm enough temperature so that it doesn’t to freeze.

That’s one thing - and the other is that you need enough atmospheric pressure, thick enough air so that the water doesn’t instantly vaporize. The Mars we see today doesn’t have either of those conditions. It’s too cold and the air is too thin. But a long time ago, there may have been a thicker atmosphere that created a greenhouse effect that raised temperatures – and maybe that combination produced water on the surface of the planet. So, maybe Mars wasn’t just a dead boring rock. Maybe it was a fascinating fossil that once was alive in dynamic – worthy of exploration. Now, let’s jump forward a few decades to the beginning of this century. And a new generation of orbiters and landers that have been sent to Mars. Of course the scientific instruments now surveying Mars are far more sophisticated than the instruments of the 70’s.  So we are getting all kinds of new data for analysis. And not surprisingly, that data is challenging our notions of what Mars is like. Lisa, you mentioned that a lot of the news reporters talked about water. Do you remember any of the details?

Well, they are showing these pictures with these long, uh, cuts in the ground which would be gullies here. I mean, on earth. They say that since, uh, gullies are usually formed by water. It seems like they might be evidence that water still exists on Mars, but I didn’t get how that worked.

I’m not surprised. There are a lot of theories, a lot of that speculation. Some argue that the formations aren’t caused by water at all. But there are some ingenious theories that assume there’s a lot of water right under the planet’s surface that is somehow causing the gullies to form. If only we can get a lander there… but gullies aren’t in places where we can send landers yet. Anyway, if there is some kind of water activity, it may change our view of the planet once again… to something that is not dead, not even a fossil, but rather a planet like Earth, that undergoes cycles. Think of our ice ages- over long periods of time. Maybe Mars can sustain water again at some distant date.

Sunday, September 1, 2013

托福听力听写练习 TOEFL LISTENING lecture of biology class

The original listening material is from ETB test.
Red marked places are mistakes i made.

Biology

Listen to part of a lecture in a biology class.

We’ve been discussing animal communication. Um, today we are going to talk about dolphins. Now, dolphins make a wide range of communicative sounds, and display something called vocal learning, which is the ability of an animal to modify its vocalizations based on its experience with other animals. There are many types of dolphin vocalizations. We still don’t know their precise meanings partly, I suppose, because we haven’t really tried that hard to figure out their precise meanings – but we do know that dolphins use vocalizations as a way of communicating with one another. And we’ve categorized their vocalizations into three types: whistles, clicks, and burst pulses. The dolphin whistles are very high frequency sounds, ah partially above the range of human hearing. What’s fascinating is, each dolphin has a signature whistle, which is unique to each individual dolphin.  It allows them to call to and identify each other.  Jennifer?

Kind of like learning someone’s name? So… do dolphin parents choose names for their children?

Well, again, that’s something we don’t know, but we do know that no two signature whistles sound identical. And, members of the same family, their signature whistles have similar elements. Dolphins use them as contact calls – ah they call to each other while travelling and foraging. It helps keep the group together, and helps mother and children find each other. Think of it like …. if you were travelling in the forest with one other person who was just out of sight, you’d call out, “are you there? and the other person would respond. But if there were several people in the forest, you would have to call that person’s name to call to them. In addition to whistles, dolphins produce clicks which are actually sonar or sound waves. They use clicks to communicate, but, more importantly to navigate and hunt. How?

Well, the sonar clicks bounce off objects, and then dolphins convert the incoming signals into a three dimensional picture… a mental map of what’ around them. Their clicks are extremely sensitive and accurate. Their sonar clicks are also very strong. And there is the theory that one reason dolphins swim side by side is to avoid interference from each other’s sonar clicks. Interference would be confusing… it would prevent them from getting an accurate picture of their surroundings. And what’s interesting is, dolphins will turn off their sonar when another dolphin passes in front. The third category of dolphin’s vocalizations is burst pulses. These are all this other sounds the dolphin makes – suawks, squeals, barks, groans, and so on. Burst pulses are used to display aggression, show dominance and attract mate. But whistles, clicks, burst pulses aren’t the only ways dolphins communicate. Does anyone remember any other ways?

 In the book, it said that they also slap their tails against water. Oh, and … the air that comes out when thye breathe or whistle … the … ah … the bubble streams? They can control how the air bubble streams come out? I thought that was really interesting.

Yes, the bubble streams are very interesting. Dolphins can identify and locate each other by their bubble streams and they can imitate the bubble steam patterns of other dolphins… sort of like saying hello. So as you can see, dolphins use many sounds and behaviors to convey messages to each other. I’d like to tell you about when I was a graduate student … and … I spent one summer on a boat in the Atlantic Ocean studying marine life. One morning, there were about 25 dolphins swimming with the boat. We can hear their whistles and clicks as they called to each other. Now, we were there as impartial scientists, to do research, but… how could we not notice the beauty as the bubble streams made patterns in the water and the dolphins appeared to dance and play? It’s wonderful if you do field work and actually experience something you‘ve been studying in a class room. So if you ever have the opportunity, go for it!