Earth's Inner Core_简答题试题答案

第1题

Earth's Inner Core Scientists have" long struggled to understand What lies at the pl

Earth's Inner Core

Scientists have" long struggled to understand What lies at the planet's center. Direct observation of its center is impossible, so researchers must ___________ (51) to other evidence.

In 1889, a German scientistdetected a severe earthquake in Japan. Geophysicists concluded that shock waves___________ (52) jolts(晃动) from one side of Earth through the center to the other side. Then in 1936, Danish geophysicist Inge Lehmann studied the waves'___________ (53) to determine that within Earth's core of molten (熔化了的)iron lies a solid inner core-- But___________ (54) that core was made of eluded (难倒)her, Other geophysicists quickly determined that Lehmann's inner core was composed mostly ___________ (55) iron. Since then, Lehmann's discovery has ___________ (56)conventional Earth science.

But now scientists are challenging traditional theory with new and radical___________ (57). For example, Earth's center could actually contain an "inner core within the inner core," claim Ishii and colleague Adam Dziewonski.

Analyzing hundreds of thousands of earthquake wave___________ (58), they maintain that the inner core has at its heart a tiny, even more solid sphere(球体). This sphere "may be the oldest fossil ___________ (59) from the formation of Earth," says Dziewonski.

Dziewonski and Ishii speculate that shortly___________ (60) Earth formed around 4.8 billion years ago, a giant asteroid (小行星) smashed into the young planet and nearly melted it. But Earth's center didn't quite melt; it___________ (61) mass as the planet cooled. The core within a core may B．e the kernel (核心) that endured. "Its presence could change our basic ideas about the___________ (62) of the planet," Dziewonski says.

Dziewonski's idea is tame (温和的) compared to the ___________ (63) theories of independent geophysicist J. Marvin Herndon. Earth's inner core is made not of iron, he claims, but a ___________ (64) of nickel and silicon. Herndon has a truly revolutionary notion: Within the nickel silicide(硅化物) inner core is also.an "inner" inner core -- an 8 kmowide ball of the element uranium. Uranium is radioactive. Herndon thinks the uranium releases heat energy as its atoms ___________ (65) fission-split and crash into one another in a chain reaction. In other words, we may live on top of a gigantic, "natural"nuclear power plant.

第 51 题

A．try

B．leave

C．turn

D．point

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第2题

根据下列文章,请回答 51～65 题。 Earth's Inner Core Scientists have long struggled to u

根据下列文章,请回答 51～65 题。

Earth's Inner Core

Scientists have long struggled to understand what lies at the planet's center. Direct observation of its center is impossible, so researchers must ________ (1) to other evidence.

In 1889, a German scientist detected a severe earthquake in Japan. Geophysicists concluded that shock waves________ (2) jolts (晃动) from one side of Earth through the center to the other side. Then in 1936, Danish geophysicist Inge Lehmann studied the waves'________(3) to determine that within Earth's core of molten (熔化了的) iron lies a solid inner core -- but ________ (4) that core was made of eluded (难倒) her. Other geophysicists quickly determined that Lehmann's inner core was composed mostly ________(5) iron. Since then, Lehmann's discovery has ________(6) conventional Earth science.

But now scientists are challenging traditional theory With new and radical ________ (7). For example, Earth's center could actually contain an "inner core within the inner core," claim Ishii and colleague Adam Dziewonski.

Analyzing hundreds of thousands of earthquake wave________ (8), they maintain that the inner core has at its heart a tiny, even more solid sphere (球体). This sphere "may be the oldest fossil ________ (9) from the formation of Earth," says Dziewonski.

Dziewonski and Ishii speculate that shortly ________ (10) Earth formed around4.8 billion years ago, a giant asteroid (小行星) smashed into the young planet and nearly melted it. But Earth's center didn't quite melt; it________(11) mass as the planet cooled. The core within a core may be the kernel (核心) that endured. "Its presence could change our basic ideas about the ________ (12) of the planet," Dziewonski says.

Dziewonski's idea is tame (温和的) compared to the ________ (13) theories of independent geophysicist J. Marvin Herndon. Earth's inner core is made not of iron, he claims, but a ________ (14) of nickel and silicon. Herndon has a truly revolutionary notion: Within the nickel silicide (硅化物) inner core is also an "inner" inner core -- an 8 km-wide ball of the element uranium. Uranium is radioactive. Herndon thinks the uranium releases heat energy as its atoms ________ (15) fission-split and crash into one another in a chain reaction. In other words, we may live on top of a gigantic, "natural" nuclear power plant.

第 51 题

A．try

B．leave

C．turn

D．point

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第3题

Listen to 6 Minute English “The Earth’s Core” and answer the following questions. 1. What

does the science fiction Journey to the Centre of the Earth tell？ 2. How do the travelers to the core of the earth come out in the fiction？ 3. How many layers does the Earth have and what are they？ 4. What is the freezing point of iron？ 5. Why is life possible according to the talk concerning the structure of Earth？ 6. How big is the Earth’s inner core？

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第4题

SECTION BPASSAGESDirections: In this section, you will hear several passages. Listen to th

SECTION B PASSAGES

Directions: In this section, you will hear several passages. Listen to the passages carefully and then answer the questions that follow.

听力原文： There were several important discoveries in the early part of last century that helped geologists develop a more accurate picture of the earth's interior. The first key discovery had to do with seismic waves. Remember they are the vibrations caused by earthquakes. Well, scientists found that they travel thousands of miles through the earth's interior. This finding enabled geologists to study the inner parts of the earth. You see, the studies revealed that these vibrations were of two types: compression, or P waves, and shear, or S waves. And researchers found that P waves travel through both liquids and solids, while S waves travel only through solid matter. In 1906, a British geologist discovered that P waves slowed down at a certain depth but kept traveling deeper. On the other hand, S waves either disappeared or were reflected back. So he concluded that the depth marked the boundary between a solid mantle and a liquid core. Three years later, another boundary was discovered that was between the mantle and the earth's crust. There is still a lot to be learned about the earth. For instance, geologists know that the core is hot. Evidence of this is the molten lava that flows out of volcanoes. But we are still not sure what the source of the heat is.

What is the important discovery about seismic waves mentioned by the instructor？

A．They occur at regular intervals.

B．They can withstand great heat.

C．They travel through the Earth's interior.

D．They can record the Earth's internal temperature.

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第5题

There are some earth phenomena you can count on, but the magnetic field, some say, is not

one of them. It fluctuates in strength, drifts from its axis, and every few 100,000 years undergoes a dramatic polarity reversal —a period when north pole becomes south pole and south pole becomes north pole. But how is the field generated, and why is it so unstable？

Groundbreaking research by two French geophysicists promises to shed some light on the mystery. Using 80 metres of deep sea sediment (沉淀物) core, they have obtained measurements of magnetic-field intensity that span 11 polarity reversals and four million years. The analysis reveals that intensity appears to fluctuate with a clear, well-defined rhythm. Although the strength of the magnetic field varies irregularly during the short tern, there seems to be an inevitable long-term decline preceding each polarity reversal. When the poles flip—a process that takes several hundred thousand years--the magnetic field rapidly regains its strength and the cycle is repeated.

The results have caused a stir among geophysicists. The magnetic field is thought to originate from molten (熔化的) iron in the outer core, 3,000 kilometers beneath the earth's surface. By studying mineral grains found in material ranging from rocks to clay articles, previous researchers have already been able to identify reversals dating back 170 million years, including the most recent switch 730,000 years age. How and why they occur, however, has been widely debated. Several theories link polarity flips to external disasters such as meteor (陨星) impacts. But Peter Olson, a geophysicist at the Johns Hopkins University in Baltimore, says this is unlikely if the French researchers are right. In fact, Olson says intensity that predictably declines from one reversal to the nest contradicts 90 percent of the models currently under study. If the results prove to be valid geophysicists will have a new theory to guide them in their quest to understand the earth's inner physics. It certainly points the direction for future research.

Which of the following titles is most appropriate to the passage？

A．Polarity Reversal :A Fantastic Phenomenon of Nature

B．Measurement of the Earth's Magnetic-Field Intensity

C．Formation of the Two Poles of the Earth

D．A New Approach to the Study of Geophysics

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第6题

There are some earth phenomena you can count on, but the magnetic field, someday is not of

them. It fluctuates in strength, drifts from its axis, and every few 100, 000 years undergo a dramatic polarity reversal-a period when north pole becomes south pole and south pole becomes north pole. But how is the field generated, and why is it so unstable？

Groundbreaking research by two French geophysicists promises to shed some light on the mystery. Using 80 meters of deep sea sediment core, they have obtained measurements of magnetic-field intensity that span 11 polarity reversals and four million years. The analysis reveals that intensity appears to fluctuate with a clear, well-defined rhythm. Although the strength of the magnetic field varies irregularly during the shout term, there seems to be an inevitable long term decline preceding each polarity reversal. When the poles flip-a process that takes several hundred thousand years--the magnetic field rapidly regains its strength and the cycle is repeated.

The results have caused a stir among geophysicists. The magnetic field is thought to originate from molten iron in the outer core, 3,000 kilometers beneath the earth's surface. By studying mineral grains found in material ranging from rocks to clay articles, previous researchers have already been able to identify reversals dating back 170 million years, including the most recent switch 730, 000 years age. How and why they occur, however, has been widely debated. Several theories link polarity flips to external disasters such as meteor impacts. But Peter Olson, a geophysicist at the Johns Hopkins University in Baltimore, says this is unlikely if the French researchers are right. In fact, Olson says intensity that predictably declines from one reversal to the next contradicts 90 percent of the models currently under study. If the results prove to be valid, geophysicists will have a new theory to guide them in their quest to understand the earth's inner physics. It certainly points the direction for future research.

Which of the following titles in most appropriate to the passage？

A．Polarity Reversal: A Fantastic Phenomenon of Nature

B．Measurement of the Earth's Magnetic-Field Intensity

C．Formation of the Two Poles of the Earth

D．A New Approach to the Study of Geophysics

点击查看答案

第7题

SECTION BPASSAGESDirections: In this section, you will hear several passages. Listen to th

SECTION B PASSAGES

Directions: In this section, you will hear several passages. Listen to the passages carefully and then answer the questions that follow.

听力原文： There were several important discoveries in the early part of the century that helped geologists develop a more accurate picture of the earth's interior. The first key discovery had to do with seismic waves. Remember, they are the vibrations caused by earthquakes. Well, scientists found that they travel thousands of miles through the earth's interior. This finding enabled geologists to study the inner parts of the earth.

You see, these studies revealed that these vibrations were of two types: compression or P-waves and shear or S-waves. And researchers found that P-waves travel through both liquids and solids while S-waves travel only through solid matter. In 1906, a British geologist discovered that P-waves slowed down at a certain depth but kept traveling deeper. On the other hand, S-waves either disappeared or were reflected back. So he concluded that the depth marked the boundary between a solid mantle and the liquid core. Three years later, another boundary was discovered, that between the mantle and the earth's crust.

There are still a lot to be learned about the earth. For instance, geologists know that the core is hot. Evidence of this is the molten lava that flows out of volcanoes. But we are still not sure what the source of the heat is.

What is the purpose of the talk？

A．To review what students know about volcanic activity.

B．To demonstrate the use of a new measurement device.

C．To explain the answer to an examination question.

D．To provide background for the next reading assignment.

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第8题

There are some earth phenomena you can count on, but the magnetic field, some say, is not

one of them. It fluctuates in strength, drifts from its axis, and every few 100,000 years undergoes a dramatic polarity reversal—a period when north pole becomes south pole and south pole becomes north pole. But how is the field generated, and why is it so unstable？

Groundbreaking research by two French geophysicists promises to shed some light on the mystery. Using 80 meters of deep sea sediment (沉淀物) core, they have obtained measurements of magnetic-field intensity that span 11 polarity reversals and four million years. The analysis reveals that intensity appears to fluctuate with a clear, well-defined rhythm. Although the strength of the magnetic field varies irregularly during the short term, there seems to be an inevitable long-term decline preceding each polarity reversal. When the poles flip—a process that takes several hundred thousand years—the magnetic field rapidly regains its strength and the cycle is repeated.

The results have caused a stir among geophysicists. The magnetic field is thought to originate from molten (熔化的) iron in the outer core, 3,000 kilometers beneath the earth's surface. By studying mineral grains found in material ranging from rocks to clay articles, previous researchers have already been able to identify reversals dating back 170 million years, including the most recent switch 730, 000 years ago. How and why they occur, however, has been widely debated. Several theories link polarity flips to external disasters such as meteor (陨星) impacts. But Peter Olson, a geophysicist at the Johns Hopkins University in Baltimore, says this is un. likely if the French researchers are right. In fact, Olson says intensity that predictably declines from one reversal to the next contradicts 90 percent of the models currently under study. If the results prove to be valid, geophysicists will have a new theory to guide them in their quest to understand the earth's inner physics. It certainly points the direction for future research.

Which of the following titles is most appropriate to the passage？

A．Polarity Reversal: A Fantastic Phenomenon of Nature.

B．Measurement of the Earth's Magnetic-Field Intensity.

C．Formation of the Two Poles of the Earth.

D．A New Approach to the Study or Geophysics.

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第9题

Questions 26 to 30 are based on the following passage. There are some each phenomena you c

an count on, but the magnetic field, someday is not of them. It fluctuates in strength, drifts from its axis, and every few 100,000 years undergo, dramatic polarity reversal-a period when North Pole becomes South Pole and South Pole becomes North Pole. But how is the field generated, and why is it so unstable？

Groundbreaking research by two French geophysicists promises to shed some light on the mystery. Using 80 metres of deep sea sediment (沉淀物) core, they have obtained measurements lots of magnetic-field intensity that span 11 polarity reversals and four million years. The analysis reveals that intensity appears to fluctuate with a clear, well-defined rhythm. Although the strength of the magnetic field varies irregularly during the short term, there seems to be an inevitable long-term decline preceding each polarity reversal. When the poles flip—a process that takes several hundred thousand years-the magnetic field rapidly regains its strength and the cycle is repeated.

The results have caused a stir among geophysicists. The magnetic field is thought to originate from molten (熔化的) iron in the outer core, 3,000 kilometers beneath the earth’s surface. By studying mineral grains found in material ranging from rocks to clay articles, previous researchers have already been able to identify reversals dating back 170 million years, including the most recent switch 730,000 years ago. How and why they occur, however, has been widely debated. Several theories link polarity flips to external disasters such as meteor (陨星) impacts. But Peter Olson, a geophysicist at the Johns Hopkins University in Baltimore, says this is unlikely if the French researchers are right. In fact, Olson says intensity that predictably declines from one reversal to the next contradicts 90 percent of the models currently under study. If the results prove to be valid geophysicists will have a new theory to guide them in their quest to understand the earth’s inner physics. It certainly points the direction for future research.

第26题：Which of the following titles is most appropriate to the passage？

A) Polarity Reversal: A Fantastic Phenomenon of Nature.

B) Measurement of the Earth’s Magnetic-Field Intensity.

C) Formation of the Two Poles of the Earth.

D) A New Approach to the Study or Geophysics.

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第10题

A．The Moon has no waterB．The Moon's materials came from Earth's coreC．The Moon's core

A．The Moon has no water

B．The Moon's materials came from Earth's core

C．The Moon's core differs from its surface

D．The Moon contains little iron

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