The Cause of Auroras托福紅Delta聽力原文翻譯及問題答案

The Cause of Auroras托福紅Delta聽力原文翻譯及問題答案，今天中國教育在線就來為大家分析這個問題。

一、The Cause of Auroras托福紅Delta聽力原文：

W:For centuries,people have told stories to explain the moving lights in the night sky—the curtains of greenish-white light with pink fringe.People described these lights as the breath of the Earth,powerful spirits,or angel light.An early twentieth-century explorer wrote about the“bloody red”and“ghostly green”lights.These lights,of course,are the aurora borealis—the northern lights—and,in the south,the aurora australis.Most of the time they’re greenish-yellow,but sometimes they take colors from violet to red.The auroras can be seen at any time of the year,with the right atmospheric conditions.They’re most often seen near the North and South Poles,during times of maximum solar activity.The closer to the North or South Pole you are,the better you can see the lights.

The auroras occur in the ionosphere.The ionosphere is the layer of the upper atmosphere where high-energy solar radiation strips electrons from oxygen and nitrogen atoms,and leaves them as positively charged ions.The auroras are the result of a complex interaction between the solar wind and the Earth’s magnetic field.Here’s what happens.The sun’s heat charges the particles in the solar wind,a stream of electrically charged subatomic particles that continually emanates from the sun.As the solar wind approaches Earth,it’s deflected by Earth’s magnetic field and diverted north and south toward the magnetic poles.The interaction between the solar wind and the magnetosphere generates beams of electrons.These electrons collide with atoms and molecules within the ionosphere near Earth’s magnetic poles.The collisions rip apart molecules and excite atoms.Thus,oxygen and nitrogen atoms in the ionosphere become“excited,”or ionized.The auroras happen when these ionized atoms return to their normal state from their excited,energized states.The ions combine with free electrons—as they do so,they emit radiation.Part of this radiation is visible light:the aurora borealis and aurora australis.Yes,Simon?

M:Uh...it sounds kind of like electricity.

W:Yes,that’s right.The auroras are an electricalphenomenon.As you know,an electrical generator has two components:a conductor and a magnetic field.To generate electricity,the conductor has to move across the field to produce a force.With the auroras,the conductor is the solar wind carrying a stream of charged particles.

M:So,what happens is,when,uh,when the charged particles reach Earth’s magnetic field,they,uh,move along in the field towards the north and south magnetic poles.

W:Exactly.And then the particles collide with gases in the atmosphere—oxygen and nitrogen—and the oxygen and nitrogen atoms get excited.And then,when the particles get de-excited and return to their normal state,they emit the auroras by releasing energy in the form of light.Oxygen releases either dark red or ghostly green.Nitrogen emits rosy pink or magenta.The activity of the auroras varies with the sun’s activity.When the sun is quiet,the auroras can be seen only in a small area.When the sun is active,however,the aurora borealis can be seen across southern Canada and the northern United States.

二、The Cause of Auroras托福紅Delta聽力中文翻譯：

W：幾個世紀(jì)以來，人們一直在講故事來解釋夜空中移動的燈光——帶粉紅色條紋的綠白色光幕。人們把這些光描述為地球的氣息、強大的靈魂或天使之光。二十世紀(jì)早期的一位探險家寫下了“血紅”和“幽靈綠”的光。當(dāng)然，這些光是北極光，北極光，南極光。大多數(shù)時候它們是綠黃色的，但有時它們的顏色從紫色變?yōu)榧t色。在適當(dāng)?shù)拇髿鈼l件下，一年中的任何時候都可以看到極光。在太陽活動最活躍的時候，它們最常出現(xiàn)在北極和南極附近。你離北極或南極越近，你就能越清楚地看到燈光。

極光出現(xiàn)在電離層。電離層是高層大氣的一層，高能太陽輻射將氧原子和氮原子中的電子剝離出來，留下帶正電的離子。極光是太陽風(fēng)和地球磁場之間復(fù)雜相互作用的結(jié)果。下面是發(fā)生的情況。太陽的熱量給太陽風(fēng)中的粒子充電，太陽風(fēng)是一股帶電的亞原子粒子流，不斷從太陽中散發(fā)出來。當(dāng)太陽風(fēng)接近地球時，它被地球磁場偏轉(zhuǎn)，轉(zhuǎn)向南北向磁極。太陽風(fēng)和磁層之間的相互作用產(chǎn)生電子束。這些電子與地球磁極附近電離層中的原子和分子發(fā)生碰撞。碰撞撕裂分子并激發(fā)原子。因此，電離層中的氧和氮原子被“激發(fā)”或電離。當(dāng)這些電離原子從激發(fā)態(tài)、激發(fā)態(tài)恢復(fù)到正常狀態(tài)時，就會出現(xiàn)極光。離子與自由電子結(jié)合時，會發(fā)出輻射。這種輻射的一部分是可見光：北極光和南極光。什么事，西蒙？

M：呃。。。聽起來有點像電。

W：是的，沒錯。極光是一種電現(xiàn)象。正如你所知，發(fā)電機有兩個組成部分：導(dǎo)體和磁場。為了發(fā)電，導(dǎo)體必須穿過磁場才能產(chǎn)生力。極光的導(dǎo)體是攜帶帶電粒子流的太陽風(fēng)。

M：所以，當(dāng)帶電粒子到達(dá)地球磁場時，它們會在磁場中向南北磁極移動。

W：沒錯。然后粒子與大氣中的氣體發(fā)生碰撞，氧和氮原子被激發(fā)。然后，當(dāng)粒子失去激發(fā)并恢復(fù)到正常狀態(tài)時，它們以光的形式釋放能量，發(fā)出極光。氧氣釋放出暗紅色或幽靈般的綠色。氮氣會發(fā)出玫瑰紅色或洋紅。極光的活動隨太陽的活動而變化。當(dāng)太陽靜止時，極光只能在一個小范圍內(nèi)看到。然而，當(dāng)太陽活動時，可以在加拿大南部和美國北部看到北極光。

三、The Cause of Auroras托福紅Delta聽力問題：

Q1:1.What aspect of the auroras does the professor mainly discuss?

A.Myths about the auroras

B.How to videotape the auroras

C.What causes the auroras 

D.The beauty of the auroras

Q2:What colors are commonly seen in the auroras?Click on two answers.

A.Orange

B.Red

C.Green

D.Brown

Q3:Why does the professor say this:

A.To compare the views from the North and South Poles

B.To explain why extremes of daylight exist at the poles

C.To point out where the auroras are most visible

D.To suggest taking a trip to the North or South Pole

Q4:Why does the professor say this:

A.To explain how the auroras are electrical in nature

B.To change the subject to something more interesting

C.To encourage the student to observe the auroras

D.To imply that the auroras contribute to global warming

Q5:The professor briefly explains how the auroras are formed.Indicate whether each sentence below is a part of the process.

For each sentence,click in the correct box.

Q6:What can be inferred about the auroras?

A.The auroras change in size and shape during the night.

B.The color of auroras is related to the type of gas involved.

C.The beauty of auroras is difficult to measure accurately.

D.The auroras are a possible source of nuclear energy.

四、The Cause of Auroras托福紅Delta聽力答案：

A1:正確答案：C

A2:正確答案：BC

A3:正確答案：C

A4:正確答案：A

A5:正確答案：ABAA

A6:正確答案：B

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