Greenhouse Effect托福听力原文翻译及问题答案

Greenhouse Effect托福听力原文翻译及问题答案

一、Greenhouse Effect托福听力原文：

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

MALE PROFESSOR:Now,over the next few weeks we’re gonna focus on carbon,and its role in what's known as the greenhouse effect.Everyone knows what that is,right?But let’s make sure,anyway. Yes, Carly?

FEMALE STUDENT:The greenhouse effect is when gases in Earth's atmosphere act like the glass in a greenhouse,or hothouse—they trap in heat,which warms up the Earth.

MALE PROFESSOR:Gases like…?

FEMALE STUDENT:Um,water vapor,carbon dioxide…

MALE PROFESSOR:Right.Carbon dioxide…We hear a lot about carbon these days,no?“Carbon emissions,”“carbon burning,”leaving a“carbon footprint”…so it'd be easy to assume that any form of carbon burning is necessarily a bad thing.But the fact is,it's not quite that simple.So,we're gonna focus today on the difference between good,bad,and,uh,well,the not-so-bad,the potentially OK carbon burning.

OK,good carbon burning—well,we all have a personal stake in this,because burning carbon is the basis of life.We wouldn't be here if we ourselves weren't“burning carbon.”Uh,basically all living things burn carbon to survive.Usually this happens at the cellular level,and what's burned is carbon in the form of sugars—glucose.

Oxygen gets chemically combined with sugars in our cells,and the energy produced from that reaction is then used to power the cells.So just by breathing you could say we're all guilty of carbon emission,and contribute to the amount of carbon in the atmosphere.

Um,another thing about atmospheric carbon:It keeps us from freezing.Because without carbon and other greenhouse gases,our planet would be the same temperature as outer space—around 4 degrees above absolute zero.And there's nothing going on at that temperature,no possibility of life of any sort.So without atmospheric carbon,life couldn't exist on Earth.

Now another thing to remember is that carbon is always being removed from the atmosphere:It gets used up.Largely it's consumed by plant life,through photosynthesis.Also,it dissolves in the oceans.Or gets stored deep in the ocean—you have shellfish that use the CO2 dissolved in the water to make carbonate shells,and when they die,they fall to the ocean floor and the carbon gets sequestered down there.

So,with all this carbon constantly being depleted from the atmosphere,we really need to keep carbon output up,to a certain point.

So why all the bad press for burning carbon?

Well,turns out it’s the source of the carbon being burned that's the key.It's in fact the burning of what we call fossil carbon that creates the imbalance—fossil fuels—coal,oil,natural gas.

These substances are all mined;we have to dig'em up,or drill a well to release them.And this is carbon that was in the atmosphere millions of years ago.

So what happens is,when we burn this carbon—OK,it doesn't really release a whole lot,compared to the amount that’s already there in the atmosphere,but it adds to the pool.And over years it accumulates.

Think of the atmosphere as a big bathtub:It’s basically already filled to the brim with carbon;when we start adding fossil carbon into the mix,it starts to spill over.Uh,That being said,there's actually a category that’s in between—what we call biomass fuels.Probably the most common one is wood.

Another example,uh,on the-the North American plains,the Native Americans used to collect buffalo droppings to burn.Uh,in Ireland they cut up peat from bogs,and they burn that.

So what's the big distinction between this and fossil carbon?

Well,biomass carbon is what we might call current carbon—Iit's always going in and out of the atmosphere.So if we burn one of these fuels,we’re putting its carbon into the atmosphere,right?But in a balanced system,somewhere else in the world this same amount of carbon is going back—it gets taken in by growing vegetation.So burning biomass fuel produces sort of“not-so-bad”carbon.In fact it can become good carbon,if we endeavor—as a society,as humanity—to allow forests to recover this carbon—if we don't,say,pave over all the surfaces to,uh,prevent things from growing.So whenever we cut down a tree and burn its wood,we have to allow another tree to grow,to keep things in balance.That way you're-you're carbon neutral.

二、Greenhouse Effect托福听力中文翻译：

旁白：在环境科学课上听讲座的一部分。

男教授：现在，在接下来的几周里，我们将重点关注碳及其在所谓的温室效应中的作用。每个人都知道那是什么，对吗？但无论如何，让我们确定一下&nbsp；是的；卡莉？

女学生：温室效应是指地球大气中的气体就像温室中的玻璃一样，或是温室中的热量，使地球变暖。

男教授：像……这样的气体…？

女生：嗯，水蒸气，二氧化碳…

男教授：对。二氧化碳……这些天我们听到很多关于碳的消息，不是吗？“碳排放”，“碳燃烧”，留下“碳足迹”……所以很容易假设任何形式的碳燃烧都是一件坏事。但事实是，这并不是那么简单。所以，我们今天将重点讨论好的、坏的，以及，呃，好的，不太坏的，潜在的OK碳燃烧之间的区别。

好的，好的碳燃烧好的，我们都有个人的利害关系，因为燃烧碳是生命的基础。如果我们自己没有“燃烧碳”，我们就不会在这里呃，基本上所有生物都是靠燃烧碳来生存的。通常这发生在细胞水平，燃烧的是以糖-葡萄糖形式存在的碳。

氧气与细胞中的糖发生化学结合，然后反应产生的能量被用来为细胞提供能量。因此，只要呼吸一下，你就可以说我们都有碳排放的罪过，并导致大气中的碳含量增加。

嗯，关于大气中的碳还有一件事：它可以防止我们结冰。因为如果没有碳和其他温室气体，我们的星球将与外层空间的温度一样，大约在绝对零度以上4度左右。在那样的温度下什么也没有发生，没有任何生命的可能。因此，如果没有大气中的碳，地球上就不可能存在生命。

现在要记住的另一件事是，碳总是从大气中被去除：它会被消耗掉。主要由植物通过光合作用消耗。此外，它在海洋中溶解。或者储存在海洋深处有贝类，它们利用溶解在水中的二氧化碳来制造碳酸盐贝壳，当它们死亡时，会掉落到海底，碳会被封存在那里。

因此，随着大气中所有的碳不断被耗尽，我们确实需要将碳产量保持在一定程度上。

那么，为什么会有这么多关于燃烧碳的负面新闻呢？

事实证明，关键在于燃烧的碳的来源。事实上，我们所说的化石碳的燃烧造成了化石燃料煤、石油、天然气的不平衡。

这些物质都是开采出来的；我们必须把它们挖出来，或者钻一口井把它们放出来。这是数百万年前存在于大气中的碳。

所以，当我们燃烧这些碳时，与大气中已经存在的碳量相比，它并没有真正释放出很多碳，但它会增加碳池。随着时间的推移，它不断积累。

把大气想象成一个大浴缸：它基本上已经充满了碳；当我们开始向混合物中添加化石碳时，它开始溢出。呃，也就是说，实际上有一个类别介于我们所说的生物质燃料之间。最常见的可能是木材。

另一个例子，呃，在北美平原上，土著美国人过去常常收集水牛粪便焚烧。呃，在爱尔兰，他们从沼泽中切下泥炭，然后焚烧。

那么这和化石碳有什么区别呢？

嗯，生物质碳就是我们所说的当前碳，它总是在大气中进出。所以，如果我们燃烧其中一种燃料，我们就会把它的碳排放到大气中，对吗？但在一个平衡的系统中，在世界其他地方，同样数量的碳正在被植物吸收回来。所以燃烧生物质燃料会产生某种“不太坏”的碳。事实上，如果我们作为一个社会，作为一个人类，努力让森林恢复这种碳，如果我们不，比如说，在所有的表面铺路，呃，阻止事物生长，它可以成为好的碳。因此，每当我们砍倒一棵树并烧掉它的木材时，我们必须让另一棵树生长，以保持事物的平衡。那样的话，你是碳中和的。

三、Greenhouse Effect托福听力问题：

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

A.To argue that carbon emissions today are not the only factor responsible for global warming

B.To provide evidence that rates of global carbon emissions fluctuate over time

C.To show the importance of distinguishing between different types of carbon emissions

D.To describe different ways carbon is removed from the atmosphere

Q2:2.What aspects of outer space does the professor emphasize?[Click on 2 answers.]

A.Its vastness

B.Its cold temperatures

C.The absence of life there

D.Its role as the ultimate source of energy on Earth

Q3:3.According to the professor,how do the oceans remove carbon from the atmosphere?[Click on 2 answers.]

A.By dissolving it

B.Through a process of condensation and precipitation

C.By storing the remains of marine animals

D.Through the regulation of air temperature

Q4:4.Why does the professor mention mining?

A.To explain why the price of fossil fuels is continually rising

B.To explain how certain fuel sources can be recovered from the ocean floor

C.To explain why coal and oil are more difficult to obtain than natural gas

D.To explain why fossil fuels contribute to an excess of carbon in the atmosphere

Q5:5.What does the professor mean when he refers to biomass carbon as"current carbon"?

A.It is the fuel source most widely approved by environmentalists today.

B.It is part of a balanced system of carbon emission and absorption.

C.It is circulated throughout the oceans by the movement of ocean water.

D.It readily combines with other carbon molecules to produce long chains.

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

A.To let students know that the term“greenhouse effect”will be tested

B.To indicate that the definition of“greenhouse effect”will be discussed

C.To suggest that his previous definition of“greenhouse effect”was imprecise

D.To acknowledge that there is controversy surrounding the use of the term“greenhouse effect”

四、Greenhouse Effect托福听力答案：

A1:正确答案：C

A2:正确答案：BC

A3:正确答案：AC

A4:正确答案：D

A5:正确答案：B

A6:正确答案：B