TOEFL-Barron模考听力文本(-Test-7).doc

Test 71 Professors OfficeProfessor: Okay Chris. Do you understand why I asked you to see me?$ Student: I guess so. I did something in class . . . I apologize.$ Professor: But do you understand whats bothering me?$ Student: No, not really. I like your class.$ Professor: Im glad you do. But Chris youre disturbing the other students with your constant talking.$ Student: I am?$ Professor: Yes. Ive had several people complain about it. Theyre missing key parts of the lecture because youre talking.$ Student: But Im talking about the lecture. Im not just making conversation.$ Professor: Look, Chris. It doesnt matter. When I am talking, you should be listening.$ Student: Well, Im sorry. Sometimes I dont get a word or a phrase so I ask someone about it.$ Professor: Okay. I really dont think youre creating a disturbance on purpose. If I did, Id simply ask you to drop the class. Period.$ Student: Oh please dont do that.$ Professor: Thats not my plan, but it has to be an option. Look, maybe you need to record the lectures. I dont mind if you do that. Then, you can fill in the blanks when you listen the second time instead of asking your neighbor during the class.$ Student: Thats a great idea. I really wanted to do that, but I was thinking you probably wouldnt want me to.$ Professor: And another thing. If you have questions, I need you to write them down and make an appointment to talk with me about them. Thats why I have office hours twice a week.$ Just call the department, and well arrange a time.$ Student: Excuse me, Dr. Pierce. Can I tell you something? Uh, Im embarrassed to ask you questions.$ Professor: Why in the world would that be? I ask for questions at the end of every lecture. I encourage students to use my office hours . . .$ Student: I know you do. Its just that where I went to school before I came here, if you asked a professor a question, it was an insult because . . . because it implied that he hadnt explained everything well. You see, if the professor does a good job on the lecture, everything will be clear and no one will need to ask a question.$ Professor: I see. Well, its different here. Im not saying that your other experience is wrong . . . Im just saying that we do things differently at the university in this country. In my class I dont expect you to understand everything in the lectures. And I dont take it as a challenge when someone asks a question. I view the question as . . . kind of a compliment . . . because it means that person is very interested and is really trying to learn. Thats the kind of student I want.$ Student: So, I can ask you questions in class?$ Professor: Or in my office. Just dont ask other students questions while Im trying to give my lecture. That does upset me.$ Student: Oh, Professor Pierce. Im so sorry. I was trying to be respectful. Im interested in the class and I want to know everything.$ Professor: I see that. Now Im asking you to show your interest and respect in a different way. I want you to ask me the questions at the times that I provide for question-and-answer- at the end of the lecture and during my office hours.$ Student: And I can record the lectures?$ Professor: Yes. Just dont make a lot of noise in class, okay?$ Student: Oh no, I wont. Thank you so much.2 Art ClassProfessor:$ Symmetry is a concept that, yes, is expressed in the graphic arts, but to understand its fundamental nature, we must go beyond art. We find symmetry in nature, it reverberates in music, translates into choreography for dance, and . . . underlies basic mathematical formulas. But Im getting ahead of myself. Lets begin with a dictionary definition of symmetry. And Im reading here from the American Heritage Dictionary of the English Language: Symmetry is “exact correspondence of form and constituent configuration on opposite sides of a dividing line or plane or about a center or an axis.” And its also identified in the same source as “beauty as a result of balance or harmonious arrangement.” So we experience beauty and harmony when symmetry of form is expressed, and the form may be interpreted by any of the senses as, uh, harmonious. But in this class were going to focus on symmetry in the visual arts, and thats symmetry in a visual plane.$ Lets just look at some examples. In general, there are four types of symmetry in a plane, and a pattern is symmetrical if theres at least one type of symmetry. So, let me show you the four types since its much easier to understand when you see them.$ This is rotation symmetry. For this example, I used the letter R, but any object could have been used. And in the rotation, the object, in this example, the letter R, is turned around a center. In this case, theres a right angle, but any angle could have been selected.$ Reflection is . . . wait a minute. Okay, heres the slide.$ Reflection is what we see in a mirror, so every reflection has a mirror line. A reflection of the letter R is a mirror image or a backwards letter R. So, unlike the rotation around a circle, this type of symmetry flips the object over.$ Heres a translation. To translate an object means that we move it, but we do it without rotation or reflection. Its simply placed somewhere else on the plane. And for our purposes, were talking about a flat plane. So, in this example, uh, we just moved it over a little bit.$ Okay, this is my last example of symmetry and its referred to as glide reflection. This is the most complex type of symmetry because it involves two steps instead of one. A glide reflection is a combination of a reflection and a translation along the direction of the mirror line. So, uh, you can see the two steps here. First, we flip it over and then we move it somewhere else on the plane.$ Of course these concepts can be generalized to include spatial symmetry as well. But, symmetry on a flat plane involves positioning all points around the plane so their positions in relationship to each remain constant . . . although their absolute positions may be subject to change. To put it in simple terms, if an object looks the same to you after you spin it around, flip it over, or look at it in a mirror, then that object probably has symmetry.$ Symmetry is such a fundamental organizing principle that an object with symmetry can be identified . . . without our being able to see the, uh, . . . the entire object. Our brains somehow piece together the missing pieces to form a symmetrical whole. Which is really rather extraordinary, when you think about it. At some very basic level, symmetry may be part of the way that we . . . that we organize our thinking.$ And of course, that would explain why its so pleasing.$ So now lets return to symmetry in art. Symmetry stands out and attracts attention. Its the system of organization for patterns. But what is a pattern? A pattern has three characteristicsa system for organization, and like we said before, this is often symmetry, but a pattern also has a basic unit, that is, uh, its an object thats the smallest discrete part of the image. As youll recall from the types of symmetry that we discussed, the letter R was the basic unit. Okay, finally, a pattern has repetition, which can be the repetition of a unit or a group of units. And, uh, this repetition, in much of art, this repetition is arranged symmetrically.$ Just look around the classroom. Look at the tiles on the floor. Here you see a symmetrical design with four repeating tiles. The tiles were not placed at random. Theres a pattern here with all three characteristics of a patternfirst, theres a unit, a basic unit, of four tiles; second, theres repetition of the tiles with solid tiles surrounding them; and, uh, third, theres symmetry . . . within the four tiles, which to be specific, looks like rotation symmetry to me.$ Now, for your studio assignment, I want you to draw a pattern that has as its organizing principle, a symmetrical design. It can be either in color or in black and white, but it must fit on a piece of standard 812 by 11-inch paper. On a second sheet of paper, I want you to identify the type of symmetry that you used. Perhaps some of you will want to experiment with several types of symmetry, but if you do, please be sure to identify each of them clearly in your narrative. For this first effort, I recommend that you stick to something relatively simple, like the tile floor. So, when you come to class next week, be ready to share your design with three other people in a group. Then Ill collect them at the end of the hour.3 Biology ClassProfessor:$ By studying the fossil record we can read the history of life on Earth. Interestingly enough, it appears that there are long periods in which not very much change occurs; then sporadic brief periods in which there are mass extinctions of species followed by diversification of the groups that survived. How does this happen? Well, sometimes a habitat is destroyed or the environment changes. Did you know that if the temperature of the ocean falls by even a few degrees, many species will die? Incredible, isnt it? Or, even when the environment is relatively stable, biological conditions can change when other species evolve in different directions. For example, lets see, when a similar species evolves by developing a shell, then the related species without shells may be more vulnerable to predators and could become extinct as a result of changes in the other species. So you can see that extinction is a natural consequence of history. Its, well, inevitable. But sometimes mass extinctions occur and most of the known species are lost. And this is very different.$ Let me mention two such mass extinctions. $ First, the Permian mass extinction, which occurred about 250 million years ago. According to fossil records, more than 90 percent of the marine species and about 30 percent of the orders of insects . . . perished. Then about 65 million years ago, the Cretaceous mass extinction claimed more than half of the marine species and many terrestrial species of plants and animals, including the dinosaurs.$ So what causes mass extinction? This isnt an easy question to answer. You see, its obvious from the fossil records that species exist during a certain geological time period, and then, they disappear, and we have solid evidence for that. But why they disappear is, well, more speculative. In the Permian, several extreme conditions may have converged, including the merging of the continents into one large land mass. As you can imagine, such a radical change in the distribution of land and water would have disturbed habitats and caused the climate to change. Theres also evidence that volcanic activity during this period may have produced enough carbon dioxide to cause global warming, which in turn would have affected the temperature and depth of the oceans, and it, and Im referring here to global warming, so it probably also caused the oxygen levels in the oceans to decrease. All of these conditions could have converged to extinguish an enormous number of species at the same time. Thats mass extinction.And, a similar set of conditions may also have contributed to the mass extinction in the Cretaceous period as well. We can gather data that convinces us about continental drift . . . that it occurred along with receding seas along the continental coastlines. In addition, we know that cooler climate was probably the result, at least in part, of . . . increased volcanic eruptions, and these eruptions probably released enough material into the atmosphere to block the sunlight. Having said all of that, many scientists now favor a very different hypothesis. They theorize that maybe a large asteroid collided with the Earth. Advocates of the so-called impact hypothesis speculate that there were two events that caused the mass extinction. First, the impact probably caused a fire storm of such proportion that most of the life in North America would have been decimated within minutes. Second, they postulate that an enormous cloud of fallout could have blocked out the sunlight and . . . that the impact was, in fact, large enough to . . . darken the Earth . . . and were talking about months or even years. So the result . . . of the darkness, I mean . . . that would have caused a reduction in photosynthesis, which, in turn, would have created a disruption in the food chain. Now, such a disruption would have affected many species.$ So the advocates of the impact hypothesis . . . they put forward evidence that a thin layer of clay, rich in iridium deposits, uh, can be found in the geologic material that separates the Mesozoic and the Cenozoic erasprecisely the time period for the Cretaceous mass extinction. So whats special about this clay?$ Well, iridium is a very rare element on Earth, but its quite common in meteorites and other extraterrestrial debris thats been analyzed. So, its possible that this sediment is the remains of the impact. The fact that there was more serious damage to the species in the Western Hemisphere could also be explained by the point of impact, and the fact that the dust cloud could have caused more acidic precipitation nearer the area of impact. Or, there may have been a number of calamities that converged simultaneously, disrupting planetary balances.But whatever the cause or causes, the fact remains that the mass extinctions occurred, and they influenced the biological diversity of our planet in profound ways. The species that survived, whether because they had genetic advantages or because they were fortunate enough to be farther from the catastrophes . . . these species became the ancestors of the species that have played important roles in biological evolutionary history.4 Students on CampusMan: Hi. How did your presentation go?$ Woman: Really well.$ Man: See. I told you.$ Woman: I know, but I was really nervous.$ Man: So what happened?$ Woman: Well, the T.A. asked for volunteers to go first, and I raised my hand right away because I wanted to get it over with before I got any more nervous than I already was.$ Man: So you went first.$ Woman: Yeah. And I used a lot of visuals. I had about twenty slides on PowerPoint, and that really helped me to stay on track. I mean, I didnt read the slides to the class or anything, but, you know, some of the titles kind of jogged my memory . . . so I knew what I wanted to say while each slide was shown.$ Man: Thats the beauty of PowerPoint.$ Woman: Of course, Im always afraid the computer program wont work . . . and then there I am without anything. But, I made overheads, you know, copies of all the slides, just in case.$ Man: So you could have used the overhead projector as a back up. Good idea.$ Woman: And I had most of the stuff on handouts so they could follow along without spending a lot of time taking notes. That way I could move along faster and get more in in ten minutes.$ Man: Yeah. Ten minutes isnt very long when youre trying to present something as complex as population density.$ Woman: Thats for sure. The maps really helped.$ Man: A pictures worth a thousand words.$ Woman: So true.$ Man: Listen, I cant remember whether you had a group or you had to present all by yourself.$ Woman: You had a choice, but I decided to do my own presentation. I dont know. Group projects are really popular but . . . you know.$ Man: I hear you. Id rather take responsibility for the whole presentation, if I were you.$ Woman: No surprises that way.$ Man: Is that one of your handouts? . . . Wow. That looks fantastic.$ Woman: Its easy. PowerPoint has an option for putting the slides on a handout.$ Man: Still, it looks so . . . professional.$ Woman: Thanks.$ Man: So did you have any questions after the presentation?$ Woman: Not really. I think people were mostly just wanting to get on with their own presentations.$ Man: But they seemed interested.$ Woman: Oh, yeah. And the T.A. said something about “getting off to such a good start,” so I felt good about that.5 Sociology ClassDr. Jackson: Last class, I asked you to read some articles about gang activity. Were trying to come up with a definition, so lets just go around the table and share what we found. Tracy, will you begin please?$ Tracy: Okay. Um, actually, I read a review of the research for sociological studies on gang activity, and I found that gangs have been prevalent for much longer than Id assumed. I was so surprised. For some reason, I thought that gang activity was a fairly recent phenomenon, but actually, one of the largest studies was carried out by Thrasher in 1936.$ Dr. Jackson: Good. Good. Im pleased that you found that. Thrashers study is a classic research investigation. Can you summarize the findings? Of the Thrasher study?$ Tracy: Sure. First, I should say that the study included more than 1300 gangs with more than 25,000 members. So . . . according to Thrasher, a gang is a group that may form spontaneously, but after that, it will . . . integrate . . . and that happens through conflict and violence. Over time, a spirit of solidarity and an attachment to a local territory kind of forms. Whats most interesting, besides the long history of gangs in the United States, the interesting part . . . its the fact that not much has changed over the years. And, oh yes, gang behavior seems pretty similar even across cultures.$ Dr. Jackson: That is interesting.$ Bill: Dr. Jackson, may I go next? I have just a brief comment that seems to fit in here.$ Dr. Jackson: Please.$ Bill: Well, another classic study, much later, about 1987 or 8, I think, by Joan Moore . . . that study indicated that gang behavior is probably caused by normal adolescent insecurities . . . the desire for peer approval, respect, support, acceptance, and, in