tpo15听力文本

tpo15听力文本内容摘要：

between these two epics. Now there is growing evidence that the presence of humans has altered the earth so much that a new epic of geologic history has began – the Anthropocene epic, a new humaninflue nced epic. T his idea that we ’ ve entered a new Anthropocene epic was first proposed in 2020. T he idea is that around the year 1800 CE the human population became large enough, around a billion people, that its activities started altering the environment. T his was also the time of the industrial revolution, which brought a tremendous increase in the use of fossil fuels such coal. The exploitation of fossil fuels has brought pla wide developments: industrialization, construction, uh, mass transport. And these developments have caused major changes like additional erosion of the Earth ’ s surface and deforestation. Also, things like the damming of rivers , has caused increased sediment production, not to mention the addition of more carbon dioxide and methane in the atmosphere . Naturally all these changes show up in recent sediments. And these sediments are quite different from pre year 1800 sediment layers. Interestingly there39。 s some speculation that h umans started having a major impact on Earth much earlier, about 8000 years ago. That39。 s when agriculture was being widespread. Early farmers started clearing forests and livestock produced a lot of extra methane. But I want to stress this is just a hypothesis. The idea that early humans could have had such a major effect, well I39。 m just not sure we can pare it with the industrial age. Geologists in the far future will be able t o examine the sediment being laid down today, whereas right now we can say that yes, human impact on the Earth is clear: It39。 ll be future researchers who have a better perspective and will be able to really draw a line between the Holocene and the Anthropocene epics. Conversation 2 Narrator Listen to part of a conversation between a student and her biology . Professor Hi Samantha, how did your track meet go? Samantha Great! I placed first in one race and third in another. Professor Congratulations ! You must practice a lot. Samantha Three times a week preseason, but now that we ’ re peting every weekend, we practice 6 days a week from 3:30 till 5:00. Professor Athletics place a heavy demand on your time, don ’ t they? Samantha Yeah, but I really love peting, so … Professor You know I played soccer in college and my biggest challenge, and I didn ’ t always succeed, was getting my studying in during soccer season. Are you having a similar … Samantha No, I … I really do make time to study. A nd I actually study more for this class than I do for all my other classes. B ut I didn ’ t see the grade I expected on my midterm exam, which is why I came by. Professor Well, you didn39。 t do badly on the exam, but I agree it did not reflect your potential. I say this because your work on the lab project was exemplary. I was so impressed with the way you handle the microscope and the samples of onion cells, and with how carefully you observed and diagramed and interpreted each stage of cell division. And I don39。 t think you could have done that if you hadn39。 t read and understood the chapter. I mean it seemed like you really had a good understanding of it. Samantha I thought so too, but I missed some questions about cell division on the exam Professor So what happened? Samantha I just sort of blanked out, I guess. I had a hard time remembering details. It was so frustrating. Professor Alright, let39。 s back up. You say you studied, where, at home? Samantha At my kitchen table actually . Professor And that39。 s supposed to be a quiet environment? Samantha Not exactly. My brother and parents try to keep it down when I am studying, but the phone pretty much rings off the hook, so … Professor So you might try a place with fewer distractions, like the library … Samantha But the library closes at midnight, and I like to study all night before a test, you know, so everything is fresh in my mind. I studied six straight hours the night before the midterm exam . T hat ’ s why I expected to do so much better. Professor Oh ok. Y ou know that studying six consecutive hours is not equivalent to studying one hour a day for six days. Samantha It isn ’ t? Professor No. There is research that shows that after about an hour of intense focus, your brain needs a break. It needs to, you know, shift gears a little. Your brain39。 s ability to absorb information starts to decline after about the first hour. So if you are dealing with a lot of new concepts and vocabul。