Renewable Energy Sources托福听力原文翻译及问题答案

Renewable Energy Sources托福听力原文翻译及问题答案

一、Renewable Energy Sources 托福听力原文：

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

FEMALE PROFESSOR: Now, there's growing interest these days in generating electricity from renewable energy sources, right? From developing wind farms, to tapping into an underground source of geothermal energy. And when you're considering a new project, it's important to look at the costs, as well as benefits, of developing that energy source. Let me give you an example of the kind of thing I’m talking about.

There’s currently a lot of interest in harnessing the power of the oceans—of the ocean tides, that is… the movement of huge amounts of water, which causes the water level of oceans to rise and fall. The idea is that if we can harness that tidal energy, it’d be a great, clean, renewable energy source.

One place where this tidal energy can be harnessed is at a shallow body of water, such as an estuary.Now, can anyone tell us what an estuary is? Yes, Ted.

MALE STUDENT: An estuary's where a river enters the ocean… the fresh water meets the ocean water. Sometimes it's covered in water; sometimes it's not…

FEMALE PROFESSOR: Some parts of the estuary—as the tides go in and out… but other parts are always submerged. 

Now, estuaries are an ideal place to try to capture energy from changes in tides because, well, there’s an exceptionally large difference between the water level at high tide and at low tide. All that movement of water generates a lot of energy. And one way to harness that energy is by building a structure called a barrage there.

A barrage is basically a large low dam that’s built across an estuary. When the tides go in and out, the moving water flows through tunnels in the barrage. So you have huge amounts of water trying to flow through these relatively small tunnels… and that turns turbines  that generate electricity.

Now, these estuaries are important because of their high level of biological productivity. They're home to lots of birds, fish, and other marine life. So when you propose to construct a barrage, you have lots of issues to consider.

For example, it would change the existing water levels in the estuary… since a lot of water is getting held up by the barrage, the incoming tides won't go as high... but they wouldn’t be as low during low tide, either. This might help prevent flooding, but it would also affect the mud flats—those areas of mud that normally are exposed when the tide recedes.

MALE STUDENT: But don't lots of birds rely on exposed mud flats for food?

I mean, don’t they eat tiny animals that live in the mud?  And what about those tiny animals? What would happen to them if the mud flats were endangered?

FEMALE PROFESSOR: So you're seeing some of the potential problems with a barrage. But consider this… Right now the water in an estuary is very cloudy. The tidal currents are constantly churning up the sediments that rivers deposit in the estuary. But a barrage would reduce the tidal currents, so a lot of that sediment would settle to the floor of the estuary; it wouldn't get stirred up so much. The water would be clearer… allowing more sunlight to reach deeper into the water… which might lead to more food for birds and other animals…attracting new wildlife to the area. So it's a complicated environmental picture.

MALE STUDENT: Have they tried this anywhere… built a barrage?

FEMALE PROFESSOR: Yes, there are several in operation. There's one in France.

They have to be careful there about how they turn on the turbines, because they create currents and waves that can affect boats.

But I haven't read about any major ecological problems. In fact, the fishing is supposed to have improved…plus there's even more bird life.

But some of the barrages we’re considering now would be much larger than that one. There's been one proposed for the estuary of Great Britain’s Severn River… one of the largest estuaries in the world. It would be 16 kilometers long… just to give you an idea, the barrage in France is less than a kilometer.

Outside of environmental concerns, such a project would be hugely expensive and that’s another argument against barrages—well, such large ones anyway. Critics say that it would be better to use that money for something else, such as improving the energy efficiency of buildings. You could make a lot of buildings more efficient with all that money, and that would reduce the need for electricity.

二、Renewable Energy Sources 托福听力中文翻译：

旁白：在环境科学课上听讲座的一部分。

女教授：现在，人们对利用可再生能源发电越来越感兴趣，对吗？从开发风电场到开发地下地热能源。当你考虑一个新项目时，重要的是要考虑开发这种能源的成本和效益。让我给你举一个我正在谈论的这类事情的例子。

目前人们对利用海洋潮汐的力量非常感兴趣，也就是说……大量的水的运动，导致海洋的水位上升和下降。我们的想法是，如果我们能够利用潮汐能，它将是一种伟大的、清洁的可再生能源。

可以利用潮汐能的一个地方是浅水区，例如河口。现在，有人能告诉我们什么是河口吗？是的，特德。

男学生：河口是河流进入海洋的地方……淡水与海水相遇。有时它被水覆盖；有时不是…

女教授：潮汐进出时，河口的一些部分……但其他部分总是被淹没&nbsp；

现在，河口是从潮汐变化中获取能量的理想场所，因为高潮和低潮时的水位相差非常大。水的运动产生了大量的能量。利用这种能量的一种方法是在那里建造一个叫做拦河坝的结构。

拦河坝基本上是一个横跨河口的低矮大坝。当潮水进出时，流动的水流通过拦河坝的隧道。因此，有大量的水试图流过这些相对较小的隧道……这会转动涡轮机；发电的。

现在，这些河口很重要，因为它们的生物生产力很高。它们是许多鸟类、鱼类和其他海洋生物的家园。所以，当你提议建造拦河坝时，你有很多问题要考虑。

例如，它会改变河口现有的水位……由于大量的水被拦河坝拦住，来潮不会涨得那么高。。。但在低潮时，它们也不会那么低。这可能有助于防止洪水泛滥，但也会影响泥滩——通常在退潮时露出的泥质区域。

男学生：但是很多鸟不是都依赖暴露在外的泥滩作为食物吗？

我的意思是，他们不吃生活在泥里的小动物吗？那些小动物呢？如果泥滩受到威胁，他们会怎么样？

女教授：所以你看到了拦河坝的一些潜在问题。但考虑到这一点……现在河口的水非常多云。潮流不断搅动着河流沉积在河口的沉积物。但是拦河坝会减少潮流，因此大量泥沙会沉降到河口底部；就不会这么激动了。水会更清澈……让更多的阳光深入水中……这可能会为鸟类和其他动物带来更多的食物……吸引新的野生动物来到该地区。所以这是一幅复杂的环境图。

男学生：他们在哪里尝试过这个……建造了一个拦河坝？

女教授：是的，有几个在运行。法国有一家。

在那里，他们必须小心如何打开涡轮机，因为它们产生的水流和波浪会影响船只。

但我没有读到任何重大的生态问题。事实上，捕鱼业本应得到改善……此外，鸟类的数量甚至更多。

但我们现在正在考虑的一些拦河坝将比那一个大得多。有人提议在英国塞文河（Severn River）的河口建造一个……世界上最大的河口之一。它将有16公里长……只是给你一个想法，法国的拦河坝不到一公里。

除了环境问题，这样一个项目将花费巨大，这也是反对拦河坝的另一个理由——不管怎样，这么大的拦河坝。批评人士表示，最好将这笔钱用于其他方面，比如提高建筑的能效。你可以用这些钱让很多建筑更有效率，这将减少对电力的需求。

三、Renewable Energy Sources 托福听力问题：

Q1:1.What is the main purpose of the talk?

A. To explain the mechanical functioning of barrages.

B. To discuss some possible ecological effects of building barrages.

C. To discuss the effects of ocean tides on coastal ecosystems.

D. To describe ways to increase biological productivity of estuaries.

Q2:2.What does the professor say about estuaries to support the claim that they are appropriate places for building barrages?

A. Estuaries undergo significant changes in water levels.

B. Estuaries attract a wide varity of animal species.

C. Estuaries are deeper than other bodies of water.

D. Most estuaries are far from resdential areas.

Q3:3.What is the professor's opinion when the man expresses concern about marine life on the mud flats?

A. She thinks the environmental impact of barrages would be worse for birds than for fish.

B. She agrees that any damage to the mud flats would probably be irreversible.

C. She feels that the situation is more complex than the man realizes.

D. She does not believe that the mud flats support a wide variety of animal species.

Q4:4.The professor mentions a change in the quantity of fish caught near a barrage in France. What most likely happened to the water in the estuary as a result of the construction of the barrage?

A. The water has become clearer.

B. The water has become saltier.

C. The water has become polluted

D. The water level has risen.

Q5:5.What does the professor say is a criticism of the proposed barrage at the Severn River in Great Britain?

A. It would damage nearby buildings.

B. It would attract harmful species to the region.

C. It would not be as large as the barrage in France.

D. it would be too expensive to build.

Q6:6.Replay: Why does the professor say this:

A. To request that the student answer in greater detail.

B. To introduce a new topic for discussion.

C. To make the student's statement more accurate.

D. To repeat a point that she had not stated clearly.

四、Renewable Energy Sources 托福听力答案：

A1:正确答案：B

A2:正确答案：A

A3:正确答案：C

A4:正确答案：A

A5:正确答案：D

A6:正确答案：C