Soil Formation托福聽力原文翻譯及問題答案

Soil Formation托福聽力原文翻譯及問題答案

一、Soil Formation托福聽力原文：

NARRATOR:Listen to part of a lecture in the geology class.MALE PROFESSOR:So,we all know soil.It's important to plant growth,right?And we know that there're different types of soil in different places and that some soils are more fertile than others.But what is soil?And how's it formed?Well,we're going to go into this in some depth,but for now let's just lay down the basics.

Soil is composed of two kinds of material:inorganic material,basically small pieces of rock,and organic material,which is animal and plant matter.

OK.So,what do you think?If I mix bits of rock with composted vegetables,will I get soil?The answer is no,because the formation of soil is a dynamic process.It involves not only the initial inputs,the raw materials,but also the transformation of those materials,and the movement of some of the materials and the loss of others.So,the inputs are bits of rock and organic matter.

Now,the bits of rock—the inorganic input to soil?uh...they come from the breakdown of rocks on Earth's surface through a process called weathering.Weathering can be either physical or chemical.Physical weathering,uh...that's when exposure to the elements over time causes a rock to break up and eventually disintegrate.Uh...of course,some rocks are more resistant to physical weathering than others.If you think of the sand particles in soil,those are the result of physical weathering,and they have the same chemical composition as the original rock.

Now,chemical weathering,uh...that's the chemical breakup of rocks.It differs from physical weathering in that the chemical properties of the minerals are actually changed.The clay minerals you find in soil are the result of chemical weathering.Clay minerals are called secondary minerals,because their composition has been altered.Okay.So we have weathered rock,which needs to be combined with organic matter.

So what does the organic input consist of?

It's the remains of plants and animals,but mostly plants.Now,just as rocks are broken down by weathering,the animal and plant residues are broken down,too.They're reduced to simple chemicals by microorganisms in a process called mineralization.And just as some rocks are more resistant than others to weathering,the compounds found in the soil's organic input resist mineralization at different rates.The compound cellulose is the major constituent of most plant tissue.It mineralizes relatively quickly.But there are woody substances in certain plants that strengthen the cell walls.They are found in smaller concentrations and their mineralization can take several years.Weathering and mineralization transform the inorganic and organic inputs in a number of ways.And it's partly from these transformations that soil gets its unique properties.

How does it work?

Uh...take the dark brown color of soil.After microorganisms have broken down the cellulose,we're left with two things:the microbe's waste and the more resistant plant material that microorganisms can't break down easily.These materials ultimately get transformed into a new material called humus.And when humus is combined with the clay minerals in soil,that's what gives soil its dark brown color.So now,if we've got clay and humus,these transformed materials,and we mix them together,we've got something very close to soil.

But soil isn't static,and there're still other processes that go into the formation of soil:the movement and loss of materials.The soil in any location isn't a uniform mixture.Its composition varies with depth.You see,mineral and organic materials move through soil vertically.Some materials move more easily than others.Water carries the more mobile materials from the upper level of soil to the lower levels.So the upper levels of the soil eventually get depleted of these materials,while the lower levels get enriched with them.And that creates distinct layers of soil as far down as the rock underlying the soil.And the materials that dissolve easily in water can get lost completely if the water carries them horizontally out of the soil and into rivers.

Now,of course,new mineral and organic material will be deposited at the surface and become incorporated into the soil,but you see how the processes of movement and loss contribute to the formation of soil.

二、Soil Formation托福聽力中文翻譯：

旁白：聽地質(zhì)學(xué)課上的部分講座。男教授：所以，我們都知道土壤。這對植物的生長很重要，對嗎？我們知道在不同的地方有不同類型的土壤，有些土壤比其他土壤更肥沃。但什么是土壤？它是如何形成的？好吧，我們將深入探討這一點(diǎn)，但現(xiàn)在我們只需奠定基礎(chǔ)。

土壤由兩種物質(zhì)組成：無機(jī)物質(zhì)（基本上是小塊巖石）和有機(jī)物質(zhì)（即動植物物質(zhì)）。

好啊那么，你認(rèn)為呢？如果我把一些石頭和堆肥蔬菜混合，我會得到土壤嗎？答案是否定的，因為土壤的形成是一個動態(tài)的過程。它不僅涉及初始投入、原材料，還涉及這些材料的轉(zhuǎn)化，以及一些材料的移動和其他材料的損失。因此，輸入的是一些巖石和有機(jī)物。

現(xiàn)在，這些巖石碎片是無機(jī)物輸入土壤的嗎？嗯它們來自于地球表面巖石的風(fēng)化過程。風(fēng)化可以是物理的也可以是化學(xué)的。物理風(fēng)化，呃。。。也就是說，隨著時間的推移，暴露在這些元素中會導(dǎo)致巖石破碎并最終崩解。嗯當(dāng)然，有些巖石比其他巖石更耐物理風(fēng)化。如果你想想土壤中的沙粒，它們是物理風(fēng)化的結(jié)果，它們的化學(xué)成分與原始巖石相同。

現(xiàn)在，化學(xué)風(fēng)化，呃。。。這是巖石的化學(xué)分解。它不同于物理風(fēng)化，因為礦物的化學(xué)性質(zhì)實際上發(fā)生了變化。你在土壤中發(fā)現(xiàn)的粘土礦物是化學(xué)風(fēng)化的結(jié)果。粘土礦物被稱為次生礦物，因為它們的成分已經(jīng)改變?？梢运晕覀冇酗L(fēng)化巖石，它需要與有機(jī)物結(jié)合。

那么有機(jī)輸入由什么組成呢？

這是動植物的遺骸，但大部分是植物?，F(xiàn)在，正如巖石被風(fēng)化分解一樣，動植物殘留物也被分解了。微生物在一個叫做礦化的過程中將它們還原為簡單的化學(xué)物質(zhì)。正如一些巖石比其他巖石更耐風(fēng)化一樣，土壤有機(jī)輸入中發(fā)現(xiàn)的化合物以不同的速率抵抗礦化。復(fù)合纖維素是大多數(shù)植物組織的主要成分。它礦化相對較快。但在某些植物中有木質(zhì)物質(zhì)可以加強(qiáng)細(xì)胞壁。它們的濃度較小，礦化可能需要幾年時間。風(fēng)化和礦化以多種方式改變無機(jī)和有機(jī)輸入。土壤之所以具有獨(dú)特的特性，部分是因為這些變化。

它是如何工作的？

嗯以土壤的深棕色為例。微生物分解纖維素后，我們剩下兩樣?xùn)|西：微生物的廢物和微生物不能輕易分解的抗藥性更強(qiáng)的植物材料。這些物質(zhì)最終轉(zhuǎn)化為一種叫做腐殖質(zhì)的新材料。當(dāng)腐殖質(zhì)和土壤中的粘土礦物結(jié)合時，土壤就會呈現(xiàn)深棕色。所以現(xiàn)在，如果我們有粘土和腐殖質(zhì)，這些轉(zhuǎn)化的物質(zhì)，我們把它們混合在一起，我們就得到了非常接近土壤的東西。

但土壤并不是靜止的，土壤的形成還有其他過程：物質(zhì)的運(yùn)動和流失。任何地方的土壤都不是均勻的混合物。其成分隨深度而變化。你看，礦物和有機(jī)物質(zhì)垂直穿過土壤。某些材質(zhì)比其他材質(zhì)更容易移動。水將流動性更強(qiáng)的物質(zhì)從土壤的上層輸送到下層。因此，上層土壤最終會耗盡這些物質(zhì)，而下層土壤則富含這些物質(zhì)。這就形成了不同的土壤層，直到土壤下面的巖石。如果水將易溶于水的物質(zhì)水平帶出土壤并流入河流，這些物質(zhì)就會完全消失。

現(xiàn)在，當(dāng)然，新的礦物和有機(jī)物質(zhì)會沉積在地表，并融入土壤中，但你可以看到運(yùn)動和流失過程如何促進(jìn)土壤的形成。

三、Soil Formation托福聽力問題：

Q1:1.What is the lecture mainly about?

A.The differences between mineralization and weathering.

B.Processes that remove minerals from soil.

C.Factors affecting the fertility of soil.

D.Several processes involved in the creation of soil.

Q2:2.What differences does the professor point out between sand particles and clay minerals?[Click on 2 answers.]

A.They combine with organic matter in different ways.

B.They are formed by different types of weathering.

C.The rocks they come from have different levels of resistance to weathering.

D.Only sand particles have the same composition as the rock they come from.

Q3:3.What does the professor point out about the compounds found in organic matter?

A.They mineralize at different rates.

B.They may resist combining with minerals in the soil.

C.They occur in roughly equal amounts in plant tissue.

D.They contain chemicals that are also found in inorganic materials.

Q4:4.Why does the professor mention the dark brown color of soil?

A.To explain that soil gets its color mainly from inorganic inputs.

B.To indicate that humus is more easily transformed than the other components of soil.

C.To show how the transformation and combination of inputs create the characteristics of soil.

D.To discuss how the characteristics of humus are changed by weathering.

Q5:5.According to the professor,how does water affect the composition of soil?[Click on 2 answers.]

A.It prevents new soil material from being incorporated.

B.It separates the components of soil into layers.

C.It causes chemical changes in the soil's organic material.

D.It can cause the loss of some of the soil material.

Q6:6.Why does the professor say this:(PROFESSOR)OK,so what do you think?If I mix bits of rock with composted vegetables,will I get soil?

A.To draw attention to the complexity of soil formation.

B.To stress the importance of organic matter in soil formation.

C.To imply that soil contains other,more important components.

D.To indicate one way soil can be formed.

四、Soil Formation托福聽力答案：

A1:正確答案：D

A2:正確答案：BD

A3:正確答案：A

A4:正確答案：C

A5:正確答案：BD

A6:正確答案：A

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