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Most people consider the landscape to be unchanging, but Earth is a dynamic body, and itssurface is continually altering-slowly on the human time scale, but relatively rapidly whencompared to the great age of Earth (about 4,500 billion years). There are two principalinfluences that shape the terrain: constructive processes such as uplift, which create newlandscape features, and destructive forces such as erosion, which gradually wear awayexposed landforms.
Hills and mountains are often regarded as the epitome of permanence, successfully resistingthe destructive forces of nature, but in fact they tend to be relatively short-lived in geologicalterms. As a general rule, the higher a mountain is, the more recently it was formed; forexample, the high mountains of the Himalayas are only about 50 million years old. Lowermountains tend to be older, and are often the eroded relics of much higher mountain t 400 million years ago, when the present-day continents of North America and Europewere 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 thecomparatively 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, whichfloat on a soft plastic layer of rock. Some mountains were formed as a result of these platescrashing 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 ofmore than 26,000 feet. Other mountains may be raised by earthquakes, which fracture theEarth's crust and can displace enough rock to produce block mountains. A third type ofmountain may be formed as a result of volcanic activity which occurs in regions of active foldmountain belts, such as in the Cascade Range of western North America. The Cascades aremade up of lavas and volcanic materials. Many of the peaks are extinct volcanoes.
Whatever the reason for mountain formation, as soon as land rises above sea level it issubjected to destructive forces. The exposed rocks are attacked by the various weatherprocesses and gradually broken down into fragments, which are then carried away and laterdeposited as sediments. Thus, any landscape represents only a temporary stage in thecontinuous 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 andpenetrates cracks in the rocks. Carbon dioxide in the air reacts with the rainwater, forming aweak acid (carbonic acid) that may chemically attack the rocks. The rain seeps underground andthe water may reappear later as springs. These springs are the 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 inpermanently cold areas, and these slowly moving masses of ice cut out valleys, carrying withthem huge quantities of eroded rock debris. In dry areas the wind is the principal agent oferosion. It carries fine particles of sand, which bombard exposed rock surfaces, therebywearing them into yet more sand. Even living things contribute to the formation oflandscapes. Tree roots force their way into cracks in rocks and, in so doing, speed theirsplitting. In contrast, the roots of grasses and other small plants may help to hold loose soilfragments together, thereby helping to prevent erosion by the wind.
Paragraph 1: Most people consider the landscape to be unchanging, but Earth is a dynamicbody, and its surface is continually altering-slowly on the human time scale, but relativelyrapidly when compared to the great age of Earth (about 4,500 billion years). There are twoprincipal influences that shape the terrain: constructive processes such as uplift, which createnew landscape features, and destructive forces such as erosion, which gradually wear awayexposed landforms.
1. According to paragraph 1, which of the following statements is true of changes in Earth'slandscape?
○They occur more often by uplift than by erosion
○They occur only at special times.
○They occur less frequently now than they once did.
○They occur quickly in geological terms.
2. The word relatively in the passage is closest in meaning to
○Unusually
○Comparatively
○Occasionally
○Naturally
Paragraph 2: 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 relativelyshort-lived in geological terms. As a general rule, the higher a mountain is, the more recently itwas formed; for example, the high mountains of the Himalayas are only about 50 million yearsold. Lower mountains tend to be older, and are often the eroded relics of much highermountain chains. About 400 million years ago, when the present-day continents of NorthAmerica and Europe were joined, the Caledonian mountain chain was the same size as themodern Himalayas. Today, however, the relics of the Caledonian orogeny (mountain-buildingperiod) exist as the comparatively low mountains of Greenland, the northern Appalachians inthe United States, the Scottish Highlands, and the Norwegian coastal plateau.
3. Which of the following can be inferred from paragraph 2 about the mountains of theHimalayas?
○Their current height is not an indication of their age.
○At present, they are much higher than the mountains of the Caledonian range.
○They were a uniform height about 400 million years ago.
○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
○Resemblances
○Regions
○Remains
○Restorations
Paragraph 3: The Earth's crust is thought to be divided into huge, movable segments, calledplates, which float on a soft plastic layer of rock. Some mountains were formed as a result ofthese plates crashing into each other and forcing up the rock at the plate margins. In thisprocess, sedimentary rocks that originally formed on the seabed may be folded upwards toaltitudes of more than 26,000 feet. Other mountains may be raised by earthquakes, whichfracture the Earth's crust and can displace enough rock to produce block mountains. A thirdtype of mountain may be formed as a result of volcanic activity which occurs in regions ofactive fold mountain belts, such as in the Cascade Range of western North America. TheCascades are made up of lavas and volcanic materials. Many of the peaks are extinctvolcanoes.
5. According to paragraph 3, one cause of mountain formation is the
○effect of climatic change on sea level
○slowing down of volcanic activity
○force of Earth's crustal plates hitting each other
○replacement of sedimentary rock with volcanic rock
Paragraph 5: The weather, in its many forms, is the main agent of erosion. Rain washes awayloose soil and penetrates cracks in the rocks. Carbon dioxide in the air reacts with therainwater, forming a weak acid (carbonic acid) that may chemically attack the rocks. The rainseeps underground and the water may reappear later as springs. These springs are thesources of streams and rivers, which cut through the rocks and carry away debris from themountains to the lowlands.
6. Why does the author mention Carbon dioxide in the passage?
○To explain the origin of a chemical that can erode rocks
○To contrast carbon dioxide with carbonic acid
○To give an example of how rainwater penetrates soil
○To argue for the desirability of preventing erosion
7. The word seeps in the passage is closest in meaning to
○Dries gradually
○Flows slowly
○Freezes quickly
○Warms slightly
Paragraph 6: Under very cold conditions, rocks can be shattered by ice and frost. Glaciers mayform in permanently cold areas, and these slowly moving masses of ice cut out valleys,carrying with them huge quantities of eroded rock debris. In dry areas the wind is the principalagent of erosion. It carries fine particles of sand, which bombard exposed rock surfaces,thereby wearing them into yet more sand. Even living things contribute to the formation oflandscapes. Tree roots force their way into cracks in rocks and, in so doing, speed theirsplitting. In contrast, the roots of grasses and other small plants may help to hold loose soilfragments together, thereby helping to prevent erosion by the wind.
8. The word them in the passage refers to
○Cold areas
○Masses of ice
○Valleys
○Rock debris
Paragraph 2: 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 relativelyshort-lived in geological terms. As a general rule, the higher a mountain is, the more recently itwas formed; for example, the high mountains of the Himalayas are only about 50 million yearsold. Lower mountains tend to be older, and are often the eroded relics of much highermountain chains. About 400 million years ago, when the present-day continents of NorthAmerica and Europe were joined, the Caledonian mountain chain was the same size as themodern Himalayas. Today, however, the relics of the Caledonian orogeny (mountain-buildingperiod) exist as the comparatively low mountains of Greenland, the northern Appalachians inthe United States, the Scottish Highlands, and the Norwegian coastal plateau.
9. Which of the sentences below best expresses the essential information in the highlightedsentence in the passage?
Incorrect choices change the meaning in important ways or leave out essential information.
○When they are relatively young, hills and mountains successfully resist the destructive forcesof nature.
○Although they seem permanent, hills and mountains exist for a relatively short period ofgeological time.
○Hills and mountains successfully resist the destructive forces of nature, but only for a shorttime.
○Hills and mountains resist the destructive forces of nature better than other types oflandforms.
Paragraph 6: Under very cold conditions, rocks can be shattered by ice and frost. Glaciers mayform in permanently cold areas, and these slowly moving masses of ice cut out valleys,carrying with them huge quantities of eroded rock debris. █In dry areas the wind is theprincipal agent of erosion. █It carries fine particles of sand, which bombard exposed rocksurfaces, thereby wearing them into yet more sand. █Even living things contribute to theformation of landscapes. █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 holdloose soil fragments together, thereby helping to prevent erosion by the wind.
10. According to paragraph 6, which of the following is both a cause and result of erosion?
○Glacial activity
○Rock debris
○Tree roots
○Sand
11. Look at the four squares [■] that indicate where the following sentence could be added tothe passage.
Under different climatic conditions, another type of destructive force contributes to erosion.
Where would the sentence best fit?
12. Directions: Three of the answer choices below are used in the passage to illustrateconstructive processes and two are used to illustrate destructive processes. Complete thetable by matching appropriate answer choices to the processes they are used to question is worth 3 points.
CONSTRUCTIVE PROCESSES DESTRUCTIVE PROCESSSES
Answer Choices：
ision of Earth's crustal plates
ration of continents
-driven sand
ation of grass roots in soil
hquakes
anic activity
her processes
參考答案：
1. ○ 4
This is a Factual Information question asking for specific information that can be found inparagraph 1. The correct answer is choice 4. Sentence 1 of the paragraph explicitly states thatEarth's landscape changes relatively rapidly compared to Earth's overall age. Choice 1, on thefrequency of landscape changes, is contradicted by the paragraph. Choice 2, that landscapechanges occur only at special times, is also contradicted by the paragraph. Choice 3, thefrequency of landscape changes, is not mentioned.
2. ○ 2
This is a Vocabulary question. The word being tested is relatively, and it is highlighted
in the passage. The correct answer is choice 2. The sentence in which relatively appears iscomparing Earth's time scale to the human time scale, so "comparatively" is the correctanswer.
3. ○ 2
This is an Inference question asking for an inference that can be supported by paragraph 2. Thecorrect answer choice 2, the Himalayas arc higher than the Caledonian mountains. Theparagraph states that younger mountains are general& higher than older mountains. Italso states that the Himalayas are much younger than the Caledonians. Since the Himalayas arethe younger range and Lounger mountain ranges are higher- than older ranges, we can inferthat the younger Himalayas are higher than the older Caledonians.
Choices 1 and 4 are incorrect because that explicitly contradict the passage. The height of theHimalayas is an indication of their age, and the Himalayas are about the same height that theCaledonians were 400 million years ago. Choice 3 is incorrect because nothing there is nothingin the paragraph about "uniform height."
4. ○ 3
This is a Vocabulary question. The word being tested is relics, and it is highlighted in thepassage. Choice 3 is the correct answer. The 1.e1ic.s of the Caledonian range are what is leftof them. "Remains" means what is left of something, so it is the correct answer.
5. ○ 3
This is a Factual Information question asking for specific information that can be found inparagraph 3. The correct answer is choice 3, mountains are formed by crustal plates hittingeach other. The paragraph states that mountains are formed in three ways: by, crustal plateshitting each other, by earthquakes, and by volcanoes. Choices 1,2, and 4 are not among thesecauses of mountain formation, so they are therefore incorrect.
6. ○ 1
This is a Rhetorical Purpose question. It asks why the author mentions "carbon dioxide" in thepassage. This term is highlighted in the passage. The correct answer is choice 1; carbon dioxideis mentioned to explain the origin of a chemical that can erode rocks. The author is describing aparticular cause of erosion, and the starting point of that process is carbon dioxide.
7. ○ 2
This is a Vocabulary question. The word being tested is seeps, and it is highlighted in thepassage. Choice 2, "Rows slowly," is the correct answer. The sentence is describing the way inwhich rain moves underground from Earth's surface. It cannot do this by "drying" (choice 1), "freezing" (choice 3), or "warming"(choice 4).
8. ○ 2
This is a Reference question. The word being tested is them, and it is highlighted in thepassage. Choice 2, "masses of ice" is the correct answer. This is a simple pronoun-referentitem. The word tlze11z refers to the glaciers that are carrying eroded rock. Notice that in thiscase, a whole series of words separates the pronoun from its referent.
9. ○ 2
This is a Sentence Simplification question. As with all of these items, a singlesentence in thepassage is highlighted:
Hills and mountains are often regarded as the epitome of permanence: successfully resistingthe destructive forces of nature, but in fact they tend to be relatively short-lived in geologicalterms.
The correct answer is choice 2. That choice contains all of the essential information in thehighlighted sentence. it omits the information in the second clause of the highlighted sentence("successfully resisting the destructive forces of nature") because that information is notessential to the meaning. Choices 1, 3, and 1 are all incorrect because they change themeaning of the highlighted sentence. Choice 1 adds information on the age of a mountain thatis not mentioned in the highlighted sentence. Choice 3 introduces information about how longmountains resist forces of nature in absolute terms; the highlighted sentence says that theresistance is relatively short in geological terms, which is an entirely different meaning. Choice 4compares mountains to other land forms. The highlighted sentence does not make any suchcomparison.
10. ○ 4
This is a Factual Information question asking for specific information that can be found inparagraph 6. The correct answer is choice 4, "sand." Sentences 3 and 4 of that paragraphdescribe erosion in dry areas. Sand is carried by wind and bombards rock; this bombardmentbreaks down the rock, and, as a result, more sand is created. Thus sand is both the cause andthe result of erosion, so choice 4 is correct. Glacial activity (choice 1) and tree roots (choice 3)are both mentioned only as causes of erosion. Rock debris (choice 2) is mentioned only as aresult of erosion.
11. ○ 1
This is an Insert Text question. You can see the four black squares in paragraph 6 thatrepresent the possible answer choices here.
Under very cold conditions, rocks can be shattered by ice and frost. Glaciers may form inpermanently cold areas, and these slowly moving masses of ice cut out valleys, carrying withthem huge quantities of eroded rock debris. ■ In dry areas the wind is the principal agent oferosion. ■ It carries fine particles of sand, which bombard exposed rock surfaces, therebywearing them into yet more sand. ■ Even living things contribute to the formation oflandscapes. ■ Tree roots force their way into cracks in rocks and, in so doing, speed theirsplitting. In contrast, the roots of grasses and other small plants may help to hold loose soilfragments together, thereby helping to prevent erosion by the wind.
The sentence provided, "Under different climatic conditions, another type of destructive forcecontributes to erosion,'' is best inserted at square 1.
Square 1 is correct because the inserted sentence is a transitional sentence, moving thediscussion away from one set of climatic conditions (cold) to another set of climatic conditions(dryness). It is at square 1 that the transition between topics takes place.
Squares 2, 3, and 4 all precede sentences that provide details of dry climatic conditions. Notransition is taking place at any of those places, so the inserted sentence is not needed.
12. ○Constructive processes 1 5 6; Destructive processes 3 7
This is a Fill in a Table question. It is completed correctly below. The correct choices for the"constructive processes” column are 1, 5, and 6. Choices 3 and 7 are the correct choices forthe "destructive processes" column. Choices 2 and 4 should not be used in either column.
大部分人認爲自然風景是一成不變的，事實上地球是一個動態的機體,他的外貌在人類文明進程中一直保持着持續緩慢的變化。當然，與大約4500億年前的冰河時代的地貌變化相比，這個進程的確快了很多。主要有兩種影響會改變地形：建設性的過程，如產生新的地表特徵的地殼隆起;和破壞性的力量，如緩慢清除突出地貌的地表侵蝕。
山峯和山脈因爲能夠經受得住自然的洗禮，通常被認作是永恆的代名詞，但地質學的角度上來說，他們的存在實際上從是相對比較短暫的。一般來說，山峯越高，形成得越晚。例如喜馬拉雅山，她只有50萬年的歷史。低矮山巒的歷史往往更加久遠，它們通常是高聳的山脈崩塌後的遺留物。在大約400萬年前，當今天的北美和歐洲大陸相結合的時候，加勒多尼亞山脈與現今的喜馬拉雅山脈同樣雄偉，但是，加勒多尼亞山脈的形成(造山運動)在今天遺留下來的卻只是相對非常低矮的格林蘭山脈：美國的北阿巴拉契亞山區，蘇格蘭高地和挪威海岸高原。
地殼分裂成爲巨大可移動的板塊，板塊在柔軟的岩石可塑層中漂移。有的時候，這些板塊互相沖擊並迫使板塊邊緣的岩石突起，從而形成山脈。在這個過程中，原本形成在海牀上的沉積岩可能被拱起高達26，000多英尺。在另一種情況下，地震將地殼震裂。產生的岩石堆積形成斷塊山，從而形成山脈。還有一種情況，活火山帶的火山運動也會促使山脈的形成，例如北美洲西部的喀斯喀特山脈，他的產生就是由火山岩和火山灰形成的，上面的許多山峯都是死火山。
不論山脈形成的'具體原因是什麼，一旦陸地高出海平面，都難逃脫被外力摧毀的厄運。裸露的岩石遭受着不斷變化天氣的攻擊，逐漸被碾成碎石塊帶走，然後形成沉積岩。因此，任何地貌都只是一個短暫的階段，它所代表的是造山與侵蝕兩種力量持續鬥爭。
多種多樣的天氣加速了大自然對地貌的侵蝕。雨水沖刷了疏鬆的土壤並滲入到岩石的縫隙。二氧化碳在空氣中與雨水相互作用形成了可以對岩石進行化學腐蝕的弱酸(碳酸)。雨水滲透到地下並能在不久後以泉水的形式流出，那些從岩石間穿過並將碎石從高山帶到平原的溪水就是來源於這些泉水。
在嚴寒的環境下，岩石能被冰霜粉碎。冰川在長期寒冷的區域形成，這些緩慢移動的大量冰塊帶着大量的腐蝕岩屑阻斷了山谷。在乾旱地帶，風是大自然侵蝕的主要手段。它帶着沙子中的微粒衝擊着裸露的岩石表面，把岩石吹散成更多的沙粒。動植物們對自然風景的形成也是功不可沒，大樹植根於巖縫之中，加速了岩石的碎裂。相比之下，草根和其他矮小植物則利於固定土壤，弱化了風蝕作用的影響。
