Lechuguilla Cave托福聽力原文翻譯及問題答案

2023-06-17 10:51:01 來源：中國教育在線

Lechuguilla Cave托福聽力原文翻譯及問題答案

一、Lechuguilla Cave托福聽力原文：

Narrator:Listen to part of a lecture in a geology class.

MALE PROFESSOR:Now,there are some pretty interesting caves in parts of the western United States,especially in national parks;there's one park that has over a hundred caves,including some of the largest ones in the world.One of the more interesting ones is called Lechuguilla Cave.Lechuguilla’s been explored a lot in recent decades.It's a pretty exciting place,I think.It was mentioned only briefly in your books,so can anyone remember what it said?Ellen?

Female Student:It's the deepest limestone cave in the U.S.MALE PROFESSOR:That’s right—it's one of the longest and deepest limestone caves not just in the country,but in the world.What else?Female Student:Well,it was formed because of sulfuric acid,right?

MALE PROFESSOR:That's it.Yeah,what happens is,you have deep,underground oil deposits.And there are bacteria...here,let me draw a diagram.

Part of the limestone rock layer is permeated by water from below.Those curly lines are supposed to be cracks in the rock.Below the water table and rock is oil.Bacteria feed on this oil,and release hydrogen sulfide gas.This gas,this hydrogen sulfide,rises up and mixes with oxygen in the underground water that sits in the cracks and fissures in the limestone.

And when hydrogen sulfide reacts with the oxygen in the water,the result of that is sulfuric acid.OK?Sulfuric acid eats away at limestone—very aggressively—so you get bigger cracks,and then passageways being formed along the openings in the rock.And it's all underground.Yes,Paul?

Male student:So that water,it's not flowing,right?It’s still?

MALE PROFESSOR:Yes!So there’s two kinds of limestone caves.In about 90 percent of them,you have water from the surface,streams,waterfall,or whatever.Moving water that flows through cracks found in the limestone.It’s the moving water itself that wears away at the rock and makes passageways.

Also,in surface water,there's a weak acid,carbonic acid—not sulfuric acid,but carbonic acid,that helps dissolve the rock.With a little help from this carbonic acid,moving water forms most of the world’s limestone caves.

When I was researching this for a study a few years ago,I visited a couple of these typical limestone caves.They were all very wet,you know?From streams and rivers.This flowing water carved out the caves and the structures inside them.Male student:But not Lechuguilla?MALE PROFESSOR:Dry as a bone.Well,that might be a bit of an exaggeration,but it’s safe to say that it’s sulfuric acid,and not moving water,that formed Lechuguilla Cave,and those few other ones like it.In fact,there’s no evidence that flowing water has ever gone in or out of the cave.So it's like a maze,you have passageways all around.There're wide passages,narrow ones,at all different depths…like underground tunnels in the limestone.

And since they were created underground and not from flowing surface water,not all of these passageways have an opening to the outside world.And there’s other evidence that flowing water wasn't involved in Lechuguilla.We've said that sulfuric acid dissolves limestone,right?And forms the passageways?What else does sulfuric acid do?Paul.Male student:It leaves a chemical residue.Um, 

Female Student:Gypsum,right?MALE PROFESSOR:Yep.You'll find lots of gypsum deposited at Lechuguilla.And,as we know,gypsum is soluble in water.So if there were flowing water in the cave,it would dissolve the gypsum.This is part of what led us to the realization that Lechuguilla is in that small group of waterless caves.And,Lechuguilla is pretty much dormant now.It's not really forming anymore…

but there's other ones like it,for example in Mexico,that are forming,and when cave researchers go to explore them,they see—and smell—the sulfuric acid and gases at work.Whew!It’s something else!Think of rotten eggs.And it's not just the smell.Explorers even need to wear special masks to protect themselves from the gases in these caves.OK.Paul?Male student:Yeah,how about what these caves look like,uh,on the inside?

MALE PROFESSOR:Oh,well,the formations are something.And there's such a variety there,like nothing anywhere else in the world!Some of them are elaborate-looking,like decorations.And a lot of them are made of gypsum,and can be up to twenty feet long.It's pretty impressive.

二、Lechuguilla Cave托福聽力中文翻譯：

旁白：聽地質學課上的一節(jié)課。

男教授：現在，在美國西部的一些地方，特別是在國家公園，有一些非常有趣的洞穴；有一個公園有一百多個洞穴，其中包括一些世界上最大的洞穴。其中一個更有趣的洞穴叫做Lechuguilla洞穴。近幾十年來，人們對Lechuguilla進行了大量探索。我認為這是一個非常令人興奮的地方。你的書中只簡要提到過它，所以有人記得它說了什么嗎？艾倫？

女學生：這是美國最深的石灰?guī)r洞穴。男教授：是的，它不僅是美國，而且是世界上最長最深的石灰?guī)r洞穴之一。還有什么？女生：嗯，它是因為硫酸而形成的，對嗎？

男教授：就是這樣。是的，發(fā)生的是，你有很深的地下石油儲量。還有細菌。。。這里，讓我畫一個圖表。

石灰?guī)r巖層的一部分被下面的水滲透。那些卷曲的線條應該是巖石上的裂縫。地下水位和巖石下面是石油。細菌以這種油為食，并釋放硫化氫氣體。這種氣體，這種硫化氫，上升并與石灰?guī)r裂縫中的地下水中的氧氣混合。

當硫化氫與水中的氧氣反應時，其結果就是硫酸。好啊硫酸對石灰石的侵蝕非常劇烈，因此會產生更大的裂縫，然后沿著巖石開口形成通道。而且都在地下。什么事，保羅？

男學生：那么水，它不會流動，對嗎？還是這樣？

男教授：是的！這里有兩種石灰?guī)r洞穴。大約90%的水來自地表、溪流、瀑布或其他地方。流經石灰?guī)r裂縫的流動水。是流動的水本身侵蝕了巖石，形成了通道。

此外，在地表水中，有一種弱酸，碳酸不是硫酸，而是碳酸，有助于溶解巖石。在這種碳酸的幫助下，流動的水形成了世界上大部分的石灰?guī)r洞穴。

幾年前，當我為一項研究而對此進行研究時，我參觀了幾個典型的石灰?guī)r洞穴。他們都很濕，你知道嗎？來自溪流和河流。這些流動的水雕刻出洞穴及其內部的結構。男學生：但不是Lechuguilla？男教授：干巴巴的。嗯，這可能有點夸張，但可以肯定地說，是硫酸，而不是流動的水，形成了Lechuguilla洞穴，以及其他幾個類似的洞穴。事實上，沒有證據表明流動的水曾經進出過洞穴。這就像一個迷宮，四周都有通道。有寬的通道，狹窄的通道，在所有不同的深度…就像石灰?guī)r中的地下隧道。

由于這些通道是在地下建造的，而不是從流動的地表水中建造的，因此并非所有這些通道都向外部世界開放。還有其他證據表明，流淌的水與Lechuguilla無關。我們說過硫酸溶解石灰石，對嗎？形成通道？硫酸還能做什么？保羅。男學生：它會留下化學殘留物。嗯；

女生：石膏吧？男教授：是的。你會發(fā)現很多石膏沉積在Lechuguilla。正如我們所知，石膏可溶于水。因此，如果洞穴中有流動的水，它會溶解石膏。這是導致我們認識到Lechuguilla在那一小群無水洞穴中的部分原因。而且，Lechuguilla現在幾乎處于休眠狀態(tài)。它不再真正形成…

但還有其他類似的洞穴正在形成，例如在墨西哥，當洞穴研究人員去探索它們時，他們會看到并聞到硫酸和氣體的氣味。呼！這是另外一回事！想想臭雞蛋。這不僅僅是氣味。探險者甚至需要戴上特殊的口罩來保護自己免受這些洞穴中的氣體的傷害。好啊保羅？男學生：是的，這些洞穴里面看起來像什么？

男教授：哦，好吧，隊形是很重要的。世界上其他地方都沒有這樣的品種！其中一些看起來很精致，像裝飾品。其中很多都是由石膏制成的，可以長達20英尺。這真令人印象深刻。

三、Lechuguilla Cave托福聽力問題：

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

A.To explain the various ways that sulfuric acid is involved in the formation of caves

B.To describe caves and other geologic formations in U.S.national parks

C.To use Lechuguilla Cave as an example of how most caves form

D.To discuss the formation and characteristics of an unusual type of cave

Q2:2.The professor mentions parts of the process involved in the formation of Lechuguilla Cave.Indicate which of the statements below describe part of the process.[Click in the correct boxes.This question is worth 2 points.]

Q3:3.According to the professor,what substance found in surface water is important for the formation of typical limstone caves?

A.Gypsum.

B.Oxygen.

C.Carbonic acid.

D.Sulfuric acid.

Q4:4.What does the presence of gypsum in Lechuguilla Cave indicate?

A.The cave was not formed by flowing water.

B.The cave is no longer forming.

C.Bacteria are present in high concentrations inside the cave.

D.No type of acid was involved in the formation of the cave.

Q5:5.What can be inferred from thefact that Lechuguilla Cave is no longer forming?

A.The cave has stopped attracting visitors.