Milankovitch Hypothesis托福聽力原文翻譯及問題答案

Milankovitch Hypothesis托福聽力原文翻譯及問題答案

一、Milankovitch Hypothesis托福聽力原文：

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

Male Professor:OK,so we've been talking about theories that deal with the effects of human activity on the climate,but today I’d like to talk a little bit about other theories that can explain variations in climate.And one of the,um,best known is called the Milankovitch hypothesis.Um,now what the Milankovitch hypothesis is about,um,it,it says that variations in Earth’s movements,specifically,in its orbit around the Sun...these variations lead to differences in the amount of solar energy that reaches Earth,and it’s these differences in the amount of energy that’s reaching Earth from the Sun,it’s what causes variations in Earth’s climate.

Okay,a lot of people think of Earth’s orbit around the Sun as being perfectly circular…as smooth and as regular as um,say the way hands move on a well-made watch.But..it just doesn’t work that way.You’re probably aware that the Earth’s orbit around the Sun,it’s not shaped like a perfect circle,it’s more of an oval,it’s elliptical.But the shape of this orbit isn't consistent,it varies over time,over a period of about 100,000 years.

Sometimes it's a little more circular,sometimes it’s more elliptical.And when Earth's orbit is more elliptical,Earth is actually closer to the Sun during part of the year,which makes Earth and in particular the Northern Hemisphere warmer.And why’s that important?Well,because most of the planet's glaciers are in the Northern Hemisphere,and if it gets too warm,then glaciers will stop forming and we already talked about how that affects Earth's overall temperature.The second movement involved in the hypothesis has to do with axial tilt,the tilt of Earth's axis,that imaginary pole that runs through the center of the Earth.And depending on the angle it tilts at,the seasons can be more or less severe–it makes winters cooler and summers warmer,or–what some might say it's doing now,it makes the summers less hot and,more importantly,the winters less cold,which,ah,just like what I mentioned before,can also stop,um,prevent glaciers from forming,or cause them to melt.There’s a third movement the hypothesis covers called precession.Precession,basically,is the change in the direction of the Earth's axis of rotation.It would take me a million years to explain even just the basics of this movement as precession is quite complex.And all of these details are way beyond our scope.What's important for you to understand is that these three movements,well,they're cyclical,and they work together to form,to produce complex but regular variations in Earth's climate,and lead to the growth or decline of glaciers.Now,when Milankovitch first proposed this theory in the 1920s,many of his colleagues were skeptical.Milankovitch didn't have any proof:Actually there wouldn't be any evidence to support his hypothesis until the 1970s,when oceanographers were able to drill deep into the seafloor and collect samples,samples which were then analyzed by geologists—

and from these samples,they were able to put together a history of ocean temperatures going back hundreds of thousands of years,and this showed that the Earth's climate had changed pretty much the way Milankovitch's hypothesis suggested it would.So this evidence was pretty strong support for the Milankovitch hypothesis,and by the 1980s,most people accepted this theory.

Um,however,in the late 1980s,some scientists were exploring Devils Hole,which is,ah,basically an extensive,water-filled cave,far from the ocean in Nevada in the western United States.Over millions of years,groundwater left deposits of a mineral called“calcite”on the rock within Devils Hole.And by studying these calcite deposits,we could determine the climate conditions...the temperatures over the last half-million years.

Well,the Devils Hole findings contradicted the ones obtained during the 1970s.So,basically,the question was,were the ages of one or both of the samples wrong?Or were scientists misunderstanding the significance of the evidence?Well,um,in the 1990s,a new study was done on the two samples,and the ocean floor samples were found to be correct,as were the samples from Devils Hole.And now it's generally believed that the samples from Devils Hole correspond to variations in local climate in the western United States,rather than global climate changes.

二、Milankovitch Hypothesis托福聽力中文翻譯：

旁白：在環(huán)境科學課上聽一節(jié)課的一部分。

男教授：好的，我們一直在討論關(guān)于人類活動對氣候影響的理論，但今天我想談?wù)勂渌梢越忉寶夂蜃兓睦碚?。其中最著名的是米蘭科維奇假說?，F(xiàn)在米蘭科維奇假說是關(guān)于，它說，地球運動的變化，特別是在它圍繞太陽的軌道上。。。這些變化導致到達地球的太陽能量的不同，正是這些從太陽到達地球的能量量的差異，才導致了地球氣候的變化。

好的，很多人認為地球圍繞太陽的軌道是完美的圓形……就像制作精良的手表上的手一樣平滑和規(guī)則。但是它就是不能那樣工作。你可能知道地球圍繞太陽的軌道，它的形狀不是一個完美的圓，它更像是一個橢圓形，它是橢圓的。但是這個軌道的形狀并不一致，它隨時間而變化，在大約100000年的時間里。

有時它更圓，有時更橢圓。當?shù)厍虻能壍栏鼨E圓時，地球?qū)嶋H上在一年中的部分時間離太陽更近，這使得地球，尤其是北半球更溫暖。為什么這很重要？嗯，因為地球上的大多數(shù)冰川都在北半球，如果溫度過高，冰川就會停止形成，我們已經(jīng)討論過這會如何影響地球的整體溫度。假設(shè)中涉及的第二個運動與軸向傾斜有關(guān)，即地軸的傾斜，即穿過地心的假想磁極。根據(jù)傾斜角度的不同，季節(jié)可能會更嚴重或更不嚴重-它使冬天更涼爽，夏天更溫暖，或者-有些人可能會說它現(xiàn)在正在做的事情，它使夏天不那么熱，更重要的是，冬天不那么冷，這，啊，就像我之前提到的，也可以阻止，嗯，防止冰川形成，或?qū)е卤ㄈ诨＿@個假設(shè)涵蓋了第三個運動，叫做進動。進動基本上是地球自轉(zhuǎn)軸方向的變化。我花了一百萬年來解釋這個運動的基本原理，因為進動相當復雜。所有這些細節(jié)都遠遠超出了我們的范圍。對你們來說，重要的是要了解這三種運動，嗯，它們是周期性的，它們共同作用形成，在地球氣候中產(chǎn)生復雜但有規(guī)律的變化，并導致冰川的增長或下降?，F(xiàn)在，當米蘭科維奇在20世紀20年代首次提出這個理論時，他的許多同事都持懷疑態(tài)度。米蘭科維奇沒有任何證據(jù)：實際上，直到20世紀70年代，海洋學家才能夠深入海底并采集樣本，然后由地質(zhì)學家分析樣本，才有任何證據(jù)支持他的假設(shè)-

從這些樣本中，他們能夠總結(jié)出幾十萬年前海洋溫度的歷史，這表明地球的氣候已經(jīng)發(fā)生了很大的變化，就像米蘭科維奇的假設(shè)所表明的那樣。因此，這一證據(jù)有力地支持了米蘭科維奇假說，到了20世紀80年代，大多數(shù)人接受了這一理論。

嗯，然而，在20世紀80年代末，一些科學家在探索魔鬼洞，這是，啊，基本上是一個廣泛的，充滿水的洞穴，遠離美國西部內(nèi)華達州的海洋。數(shù)百萬年來，地下水在魔鬼洞的巖石上留下了一種叫做“方解石”的礦物沉積物。通過研究這些方解石礦床，我們可以確定氣候條件。。。過去50萬年的氣溫。

嗯，魔鬼洞的發(fā)現(xiàn)與20世紀70年代的發(fā)現(xiàn)相矛盾。所以，基本上，問題是，一個或兩個樣本的年齡是否錯誤？還是科學家誤解了證據(jù)的重要性？嗯，在20世紀90年代，對這兩個樣本進行了一項新的研究，發(fā)現(xiàn)海底樣本是正確的，就像魔鬼洞的樣本一樣?，F(xiàn)在人們普遍認為，來自魔鬼洞的樣本對應的是美國西部當?shù)貧夂虻淖兓皇侨驓夂蜃兓?/p>

三、Milankovitch Hypothesis托福聽力問題：

Q1:1.What is the lecture mainly about?

A.A hypothesis that explains how changes in Earth’s motions affect climate

B.A hypothesis that explains why the shape of Earth’s orbit varies over time

C.Reasons it is difficult to find evidence to support hypotheses about the climate

D.Analyses of the accuracy of data collected in different ways

Q2:2.Why does the professor compare Earth’s movements to a watch?

A.To clarify a common misunderstanding

B.To show in what way Earth is similar to a watch

C.To emphasize the regularity of Earth s movements

D.To connect the concepts of orbits and time

Q3:3.Why does the professor mention Northern Hemisphere glaciers?

A.They have a significant effect on the axial tilt of Earth.

B.They play a moderating role on Earth's climate.

C.Their formation could be affected by changes in Earth s orbit.

D.Their melting could result in longer warm seasons.

Q4:4.What is the significance of the evidence found on the ocean floor?

A.It negated earlier evidence that Milankovitch found.

B.It led to the development of new methods to measure global climate changes.

C.It helped Milankovitch first formulate his hypothesis.

D.It confirmed Milankovitch’s hypothesis.

Q5:5.What did calcite deposits from Devils Hole reveal?

A.Inaccurate information about long-term climate changes

B.Evidence that contradicted Milankovitch s hypothesis

C.Evidence that climate changes occur only locally

D.Variations in Earth's orbit that had little impact on climate

Q6:6.Why does the professor say this:

A.To inform the students about what he will not discuss.

B.To indicate the difficulty of measuring precession.

C.To explain why he plans to spend a long time discussing precession.

D.To clarify that he will provide additional information later.

四、Milankovitch Hypothesis托福聽力答案：

A1:正確答案：A

A2:正確答案：A

A3:正確答案：C

A4:正確答案：D

A5:正確答案：B

A6:正確答案：A

>> 雅思 托福 免費測試、量身規(guī)劃、讓英語學習不再困難<<