TPO55听力Lecture3原文+MP3+题目+答案下载

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TPO55听力Lecture3原文+MP3+题目+答案下载

TPO55听力Lecture3原文:

Listen to part of a lecture in an astronomy class. The professor is discussing auroras.

Okay. The aurora.The aurora refers to the rays of bright colors in the night sky near the North and South Poles. In the Northern Hemisphere, it's called the aurora borealis. And in the Southern Hemisphere, it's called the aurora australis. You've probably seen pictures of it.It's quite beautiful.lt took centuries to figure out what's behind these beautiful colors in the night skies.

In the early 1700s, scientists proposed that there was an electric current that stretched between the North and South Poles, and that if this electric current was disturbed, an aurora would form.Others postulated that the phenomenon was caused by light that refracted off glaciers and snow in the Arctic.

Then in the 1800s, scientific interest in Earth's magnetic field and strange variations in Earth's magnetic field led to the observation that the biggest magnetic disturbances coincided with dramatic auroras, and also with the timing of the most intense sunspot activity. Sunspots were first observed centuries earlier, temporary dark spots on the face of the sun. They are gaseous, highly magnetic regions that move across the sun's surface.Sunspots' cycles are at their height every eleven years, and so are aurora cycles. They peak together.

By the early 20th century, it was found that Earth's magnetic field is constantly being bombarded by charged particles streaming from the sun. We call it solar wind. And do I need to tell you when the solar wind is especially strong?Yup! Every eleven years! When the magnetic activity of sunspots is peaking.The charged particles interact with Earth's magnetic field and they are pulled toward the North and South Poles.Some of them make it into our upper atmosphere where they collide with atoms, with oxygen and nitrogen atoms.............此处省略1000字

TPO55听力Lecture3题目：

1.What is the main purpose of the lecture?

A.To compare current theories about an astronomical phenomenon.

B.To describe the growth of knowledge about an astronomical phenomenon.

C.To illustrate how astronomical theories based on incorrect assumptions can lead toimportant discoveries.

D.To demonstrate that astronomers are able to predict events on the Sun based onconditions on Earth.

2.According to the professor, what theories were proposed in the 1700s toaccount for the occurrence of auroras? Click on 2 answers

A.Auroras are caused by light refracting off ice and snow.

B.Auroras are caused by CMEs.

C.Auroras occur when gases from sunspots hit glaciers.

D.Auroras occur when an electric current between Earths poles is disrupted.

3.Why does the professor mention the duration of solar eclipses?

A.To demonstrate the importance of the coronagraph as a research tool.

B.To describe the effects of solar eclipses on auroras.

C.To support a conclusion about the connection between sunspot cycles and othersolar events.

D.To explain why auroras are infrequent.

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