[分享] 戴爾美語練功坊 托福閱讀實力測驗題 5/30
戴爾美語練功坊 托福閱讀實力測驗試題(5/30日)
Causes of Ice Ages
Geologists have shown that for about 80 percent of the past 2.5 million
years, ice-age conditions have prevailed on the Earth's surface. During
the past one million years, increased glacial conditions have run in cycles
of approximately 100,000 years.
→ Many different factors may contribute to these increases in glaciations
at regular intervals throughout Earth's more geologically recent history.
(A)■ The three most prominent factors probably relate to the amount of
sunlight that reaches the Earth. This varies over time for three main
reasons. First, the planet wobbles as it spins, due to the pull of the sun
and moon. (B)■ Furthermore, the Earth tilts on its axis and the degree of
tilt changes over time. (C)■ Finally, the orbit of the Earth around the sun
is elliptical and the length of the major axis of the ellipse changes over
a period of about 100, 000 years. (D)■ A mathematician named Milutin
Milankovitch discovered in the 1930s that the pattern of insolation, or
sunlight, predicted by these eccentricities in the Earth's movement
matched the period of the last several eras of intense glaciation.
These Milankovitch insolation cycles were the dominant theory in ice-age
research for much of the twentieth century despite the fact that the
match between periods of peak insolation and most intense glaciations
were not exact. For example, a cycle of 400,000 years predicted by
Milankovitch theory has never shown up in the climate records obtained
through the study of microfossils deposited on the sea floor. Also, recent
analysis has shown that the insolation theory predicts peaks of sunlight
at intervals of 95,000 and 125,000 years. Climatological data does not
support this predicted sunlight peaking. Other damaging evidence was
the indication of a precisely measured sudden rise in temperature at a
water-filled cave in Nevada, which preceded the increase in solar
radiation that was supposed to cause it.
→ These and other problems with the Milankovitch cycles led some
researchers to seek alternative explanations for the cyclic arrival of
extended ice ages. In the 1990s, it was discovered that the orbital
inclination of the Earth to the sun and planets could also be responsible
for climate changes. If we imagine a flat plane with the sun in the center
and the planets revolving around it, the Earth slowly moves in and out
of the flat plane by a few degrees, repeating the cycle every 100,000
years. Two scientists, Muller and MacDonald, have proposed that it is
this orbital inclination which is ultimately responsible for the periods of
glaciation and warming. They argue that because of the oscillation, the
Earth periodically travels through clouds of debris, in the form of dust
and meteoroids. Such debris could reduce the amount of solar energy
reaching the surface of our planet, thus plunging it into regular cold
periods.
The advantage of this theory is that it is not confronted with several of
the problems associated with the Milankovitch theory. In particular, the
new theory fits well with the analysis of ocean sediments taken from
eight locations around the world. This analysis yielded data clearly
showing the peak of the last several ice ages with a period of 100,000
years and corresponding to the periods when the Earth's oscillating
inclination takes it through clouds of extraterrestrial debris.
However, many researchers in this field are not yet persuaded by the
inclination hypothesis. The main problem is that the amount of dust
that falls to the ground when the Earth travels through space debris is
relatively small --- not enough to produce radical climate changes.
Volcanic eruptions, for example, release much greater amounts of ash
and dust and have relatively little effect on climate. Supporters have
countered that the by-products created by the dust as it vaporizes on
entering the atmosphere cause subtle changes to the energy levels.
Nevertheless, the necessary physical proof has yet to be found to
convince the skeptics.
? wobble: shake or move from side to side
tilt: to be in a sloping position
1. The word " prevailed " in the passage is closest in meaning to
(A) ruled
(B) existed
(C) survived
(D) triumphed
2. What can be inferred from paragraph 2 about the factors that
contribute to glaciation?
(A) They affect the Earth's spin.
(B) They are geologically recent.
(C) Only three factors relate to levels of sunlight.
(D) Other factors than those relating to the sunlight affect ice buildup.
Paragraph 2 is marked with an arrow (→)
3. The phrase " these eccentricities "in the passage refers to all the
following EXCEPT
(A) the various movements of the Earth as it spins
(B) the degree of change in the Earth's tilt over time
(C) the pattern of insolation matching the Earth's movement
(D) the changing distance to the sun during the Earth's elliptical orbit
4. Scientists accepted the Milankovitch theory even though
(A) the peaks of sunlight occurred at intervals of 95,000 and 125,000
years.
(B) the peaks of insolation and intense glaciation did not match.
(C) there were climate records of a 400,000-year cycle.
(D) there were microfossil deposits on the sea floor.
5. In paragraph 4, why does the author suggest the image of a flat plane?
(A) To help the reader visualize the positions and movements of the
heavenly bodies
(B) To demonstrate to the reader how the Earth orbits the sun
(C) To support the argument that the orbital inclination increases tilting
(D) To show how Milankovitch theory doesn't explain the cyclical
changes in climate
Paragraph 4 is marked with an arrow (→)
6. The word " it " in the passage refers to
(A) such debris
(B) solar energy
(C) the surface
(D) our planet
7. In paragraph 4, the author explains that
(A) Milankovitch did not know about the orbital inclination of the Earth.
(B) glaciation occurs when the orbital inclination has entered a new cycle.
(C) the Earth always travels through clouds of debris after moving out
of the plane by a few degrees.
(D) the amount of solar energy reaching the Earth's surface causes the
changes of temperature.
8. What problem in the Milankovitch theory was mentioned as being
explained by the Muller and Macdonald theory?
(A) The climate records obtained by studying microfossil deposits not
matching his predicted cycle
(B) The irregularities of the Earth's movements through orbital
inclinations not following any pattern
(C) The Earth's spin wobbling in relation to the Earth's oscillation
inclination
(D) The peak in the ice ages occurring at intervals between 95,000 and
125,000 years instead of 400,000
9. The word " radical " in the passage is closest in meaning to
(A) violent
(B) convincing
(C) moderate
(D) transitory
10. What problem is associated with the Muller and MacDonald theory?
(A) The amount of debris that is released from volcanoes is proportional
to the amount of interstellar dust.
(B) The amount of ash from volcanoes and space dust that vaporizes in
the atmosphere is too small.
(C) The amount of dust entering the atmosphere is less than the amount
of ash and dust released by volcanoes.
(D) The by-products created by vaporized space dust cause relevant
changes to the energy levels.
11. Look at the four squares [(A) ■ (B)■ (C)■ (D)■] that indicate where the
following sentence could be added to the passage. Circle the letter that
shows the point where you would insert this sentence.When the Earth
is at its furthest from the sun, less sunlight reaches the
surface.
Where would the sentence best fit?
Click on a square (■) to add the sentence to the passage.
12. Directions: Select the appropriate phrases from the answer choices
and match them to the flaws in the ice-age theories to which they relate.
TWO of the answer choices will NOT be used.
Write the letters of the answer choices in the spaces where they belong.
Refer to the full passage.
Flaws in the Milankovitch Cycles Theory:
●___________________
●___________________
●___________________
●___________________
Flaws in the Muller and Macdonald Theory:
●_________________
●_________________
●_________________
Answer Choices:
(A) Data of climate records not convincing with predicted intervals of
sunlight
(B) Temperature rises occurring before the increase of sunlight
(C) The irregularities of the Earth's movement during its orbit around
the sun
(D) The inconsistency between the periods of sunlight and glaciation
(E) The relatively mild effect of volcanic eruptions on the climate
(F) The orbital inclination of Earth through clouds of debris
(G) The relatively small amount of interstellar debris reaching Earth
(H) The lack of clear support from ocean sediment data
(I) The lack of physical evidence in support of the effects of the inclination
hypothesis
Answers: 1. B 2. D 3. C 4. B 5. A 6. D 7. D 8. A 9. A 10. C 11. D
12. Milankovitch : A/B/D/H
Muller and Macdonald: E/G/I
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