TOEFL IBT Listening Practice Test 26 Solution & Transcripts

N Listen to part of a science lecture.

P: Before we get Into the controversial topic of cold fusion, let’s briefly review nuclear fusion In general, shall we? In order to create fusion, a lightweight atom such as tritium or deuterium must be combined with a nucleus of heavier weight, such as helium. The matter is heated and converted Into energy. The most obvious example of nuclear fusion Is the explosion of a hydrogen bomb. After the initial explosion of an atomic bomb, the Intense heat would create an explosive nuclear fusion of hydrogen. And, what’s hydrogen? Why, a mixture of tritium and deuterium, of course.

In those terms fusion sounds like a simple enough procedure, while in actuality it is extremely tricky. The reason fusion is so difficult to achieve is that the reaction requires matter that is in a superheated state. By superheated, I mean hotter than anything you can imagine. This matter Is called plasma, and millions of degrees are needed for it to develop. As plasma heats up It spreads out quickly and extends a long distance before any fusion can take place. Since we don’t have that much room In our laboratories In order to create a number of reactions, this plasma has to be compressed.

So, in fact, fusion is not that easy after all. Not the fusion that we need anyway. Now, I’m sure you know I’m not talking about building bombs. Most humans have a much more practical plan for fusion, that Is … if we can just figure out how to make it work. What I’m talking about Is hydrogen energy, of course. There is enough of this fuel in our oceans that, If we could use it, we would not have to worry about meeting our energy needs for millions of years. The Sun, which is hydrogen powered, fuses 520 gallons of hydrogen gas per second. Talk about efficient. Unfortunately, the same theory used to build a hydrogen bomb Is not going to work when we try to develop an efficient energy source. This Is because the bomb Is an uncontrolled reaction. We need a reactor that we can have complete control of in order for it to be functional. Is everyone following? OK. Good.

This leads us to the human Interest In cold fusion. Unlike high temperature fusion, cold fusion, if It could be achieved, would not require such a wide area for a reaction. In fact, for years now, a number of chemists have been trying to prove that a simple test tube Is big enough for cold fusion to take place. The problem Is that fusion cannot occur without an outside force; a magnetic field prevents the two nuclei from blending. Under high temperatures the atoms move very quickly and can outsmart this magnetic field. Despite all of the efforts of scientists and physicists, to this date, no one has been successful In creating significant energy using cold fusion. More energy Is required to create the fusion than the fusion can emit.

I have to point out a funny piece of Information here before we go any further. In recent years, cold fusion has been a subject of such heated debate that scientists have officially changed the name of work that is done In this field to either “Condensed Matter Nuclear Science” or “Low Energy Nuclear Reaction.” So, don’t be surprised if you ever come across a serious scientist who refuses to talk about cold fusion. Where were we … oh, right, I was just about to mention Stanley Pons and Martin Flelschmann. These are the two chemists who created the Initial buzz related to this field of nuclear science. In 1989, after claiming to have found the secret to creating excess energy through cold fusion, Pons and Fleischmann attempted to convince the rest of the science world that cold fusion could be achieved. Their failed attempt had the opposite effect, however, convincing many scientists that cold fusion might be even less achievable than was originally thought.


N Listen to a conversation between a student and a librarian.

S: Hi, I was wondering if you could help me.

L: Sure. Are you looking for a book?

S: Yes, In fact, I am … but I don’t have the title of the book. I’m just looking for some Information, and I’m hoping you can suggest some references.

L: OK…

S: I’m doing a paper on national Identity … and I need …

L: National Identity? You mean, like, nationalism?

S: No, no, those are two different things.

L: OK, sorry, I’m new here and I’m still learning a few things.

S: OK … uh, anyhow, I have a couple of references on national identity, They’re general references. What I need Is a research paper or book on something more specific—the way national Identity Is expressed In a European country, preferably France or Germany.

L: You’ve checked the shelves?

S: Yes, I have … and just so you know, I checked the library’s web site for books and research papers, but I didn’t find anything.

L: OK … give me a second while I think of something. Well, your best bet might be to get a list of magazines, journals …

S: Oh, right, I didn’t think of that. Uh, are the magazines listed according to topic?

L: Well, that’s the nice thing about our database. You can define your search … by date, by topic, by country … and it will give you a list and rate that list according to how relevant It Is to your topic.

S: Oh, good!

L: So … why don’t we Input your specifications. OK … any particular time period?

S: Oh … the past twenty, thirty years should be OK.

L: OK, France or Germany?

S: Try both.

L: France, Germany, national Identity and … here we go, Just give It a few seconds … and there’s your list.

S: That many?

L: Um, some of them are in the French and German languages. And you’d have to go through the English sources one by one and check which ones are relevant to your topic. Then drag It to your save box, like this. And as soon as you have a list of the magazines you definitely want to use, you can print the specific pages you need.

S: Terrific! Uh, can I use any of the computer terminals here?

L: There’s one over to your right that’s not being used. Just log in, click on the link research, then click on journals and magazines and do the same thing I did.

S: Do I have to pay for the printouts?

L: Well, it’s a very nominal fee of 10 cents a page. Just input your ID card number and pay at the counter to my left. You can use the receipt to collect your printouts.

S: OK. Thanks for the helpl

L: No problem,