戴爾美語練功坊 托福閱讀實力測驗題 7/10 - 英檢

戴爾美語練功坊 托福閱讀實力測驗試題(7/10日)

Geology and Landscape

Most people consider the landscape to be unchanging, but
Earth is a dynamic body, and its surface is continually altering -slowly
on the human time scale, but relatively rapidly when compared to the
great age of Earth (about 4.5 billion years). There are two principal
influences that shape the terrain : constructive processes such as uplift,
which create new landscape features, and destructive forces such as
erosion, which gradually wear away exposed landforms.

Hills and mountains are often regarded as the epitome of
permanence, successfully resisting the destructive forces of nature,
but in fact they tend to be relatively short-lived in geological terms.
As a general rule, the higher a mountain is, the more recently it was
formed, for example, the high mountains of the Himalayas are only
about 50 million years old. Lower mountains tend to be older, and are
often the eroded relics of much higher mountain chains. About 400
million years ago, when the present-day continents of North America
and Europe were joined, the Caledonian mountain chain was the same
size as the modern Himalayas. Today, however, the relics of the
Caledonian orogeny ( mountain-building period) exist as the
comparatively low mountains of Greenland, the northern Appalachians
in the United States, the Scottish Highlands, and the Norwegian coastal
plateau.

The Earth's crust is thought to be divided into huge, movable
segments, called plates, which float on a soft plastic layer of rock. Some
mountains were formed as a result of these crustal plates crashing into
each other and forcing up the rock at the plate margins. In this process,
sedimentary rocks that originally formed on the seabed may be folded
upwards to altitudes of more than 26, 000 feet. Other mountains may
be raised by earthquakes, which fracture the Earth's crust and can displace
enough rock to produce block mountains. A third type of mountain may
be formed as a result of volcanic activity which occurs in regions of
active fold mountain belts, such as the Cascade Range of western North
America. The Cascades are made up of lavas and volcanic materials.
Many of the peaks are extinct volcanoes.

Whatever the reasons for mountain formation, as soon as land
rises above sea level it is subjected to destructive forces. The exposed
rocks are attacked by the various weather processes and gradually
broken down into fragments, which are then carried away and later
deposited as sediments. Thus, any landscape represents only a
temporary stage in the continuous battle between the forces of uplift
and those of erosion.

The weather, in its many forms, is the main agent of erosion.
Rain washes away loose soil and penetrates cracks in the rocks. Carbon
dioxide in the air reacts with the rainwater, forming a weak acid (carbonic
acid) that may chemically attack the rocks. The rain seeps underground
and the water may reappear later as springs. These springs are sources
of streams and rivers, which cut through the rocks and carry away debris
from the mountains to the lowlands.

Under very cold conditions, rocks can be shattered by ice and
frost. Glaciers may form in permanently cold areas, and these slowly
moving masses of ice cut out valleys, carrying with them huge quantities
of eroded rock debris. (A)■ In dry areas the wind is the principal agent
of erosion. (B)■ It carries fine particles of sand, which bombard exposed
rock surfaces, thereby wearing them into yet more sand. (C)■ Even
living things contribute to the formation of landscapes. (D)■ Tree roots
force their way into cracks in rocks and, in so doing, speed their splitting.
In contrast, the roots of grasses and other small plants may help to hold
loose soil fragments together, thereby helping to prevent erosion by the
wind.


1. According to paragraph 1, which of the following statements is true
of changes in Earth's landscape?
(A) They occur more often by uplift than by erosion
(B) They occur only at special times.
(C) They occur less frequently now than they once did.
(D) They occur quickly in geological terms.

2. The word "relatively" in the passage is closest in meaning to
(A) deliberately
(B) comparatively
(C) occasionally
(D) thoroughly

3. Which of the following can be inferred from paragraph 2 about the
mountains of the Himalayas?
(A) Their current height is not an indication of their age.
(B) At present, they are much higher than the mountains of the
Caledonian range.
(C) They were a uniform height about 400 million years ago.
(D) They are not as high as the Caledonian mountains were 400
million years ago.

4. The word "relics" in the passage is closest in meaning to
(A) resemblances
(B) recuperations
(C) remains
(D) restorations

5. According to paragraph 3, one cause of mountain formation is the
(A) effect of climatic change on sea level
(B) slowing down of volcanic activity
(C) force of Earth's crustal plates hitting each other
(D) replacement of sedimentary rock with volcanic rock

6. Why does the author mention "Carbon dioxide" in the passage?
(A) To explain the origin of a chemical that can erode rocks
(B) To contrast carbon dioxide with carbonic acid
(C) To give an example of how rainwater penetrates soil
(D) To argue for the desirability of preventing erosion

7. The word "seeps" in the passage is closest in meaning to
(A) dries gradually
(B) flows slowly
(C) freezes quickly
(D) warms slightly

8. The word "them" in the passage refers to
(A) cold areas
(B) masses of ice
(C) valleys
(D) rock debris


9. Which of the sentences below best expresses the essential information
in the highlighted sentence in the passage? Incorrect choices change
the meaning in important ways or leave out essential information.

Hills and mountains are often regarded as the epitome of permanence,
successfully resisting the destructive forces of nature, but in fact they
tend to be relatively short-lived in geological terms.

(A) When they are relatively young, hills and mountains successfully
resist the destructive forces of nature.
(B) Although they seem permanent, hills and mountains exist for a
relatively short period of geological time.
(C) Hills and mountains successfully resist the destructive forces of
nature, but only for a short time.
(D) Hills and mountains resist the destructive forces of nature better
than other types of landforms.


10. According to paragraph 6, which of the following is both a cause
and result of erosion?
(A) Glacial activity
(B) Rock debris
(C) Tree roots
(D) Sand


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.

Under different climatic conditions, another type of destructive
force contributes to erosion.

Where would the sentence best fit?
Click on a square (■) to add the sentence to the passage.


Answers:
1. D --- Most people consider the landscape to be unchanging, but
Earth is a dynamic body, and its surface is continually altering -slowly
on the human time scale, but relatively rapidly whencompared to the
great age of Earth (about 4.5 billion years).

2. B --- relatively 相對地 = comparatively

3. B --- Lower mountains tend to be older, and are often the eroded
relics of much higher mountain chains. About 400 million years ago,
when the present-day continents of North America and Europe were
joined, the Caledonian mountain chain was the same size as the modern
Himalayas.

4. C --- relics 遺跡/ 遺址 = remains = remainders = ruins = vestige

5. C --- Some mountains were formed as a result of these crustal plates
crashing into each other and forcing up the rock at the plate margins.

6. A --- 此題為 rhetorical purpose (修辭目的題) ; The weather, in its
many forms, is the main agent of erosion. Rain washes away loose soil
and penetrates cracks in the rocks. Carbon dioxide in the air reacts with
the rainwater, forming a weak acid (carbonic acid) that may chemically
attack the rocks.

7. B --- seep 滲入

8. B --- Glaciers may form in permanently cold areas, and these slowly
moving masses of ice cut out valleys, carrying with them huge quantities
of eroded rock debris.

9. B --- Hills and mountains are often regarded as the epitome of
permanence, successfully resisting the destructive forces of nature,
but in fact they tend to be relatively short-lived in geological terms.
高山或山丘經常被視為永久之象徵意涵, 且成功地抵擋大自然之破壞力量;
然而事實上, 它們在地質年代中是卻是相對年代較短之景象.

10. D --- In dry areas the wind is the principal agent of erosion. It carries
fine particles of sand, which bombard exposed rock surfaces, thereby
wearing them into yet more sand.

11. A --- Under different climatic conditions, another type of destructive
force contributes to erosion.
在各種不同之氣候條件下, 另一種破壞性之力量導致侵蝕作用. 前段已
論述各種氣候之影響; 後續談及wind 吹襲沙粒形成另一種侵蝕作用.
因此該句插入於 A.




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