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 4,500 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 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 in 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 reason 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 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 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 principal agent 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 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 hold loose soil fragments together, thereby helping to prevent erosion by the wind.
　　Paragraph 1: 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 4,500 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.
　　1. According to paragraph 1, which of the following statements is true of changes in Earth's landscape?
　　○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 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.
　　3. Which of the following can be inferred from paragraph 2 about the mountains of the Himalayas?
　　○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, called plates, which float on a soft plastic layer of rock. Some mountains were formed as a result of these 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 in the Cascade Range of western North America. The Cascades are made up of lavas and volcanic materials. Many of the peaks are extinct volcanoes.
　　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 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 the sources of streams and rivers, which cut through the rocks and carry away debris from the mountains 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 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. 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. Even living things contribute to the formation 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 hold loose soil fragments 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 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.
　　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.
　　○When they are relatively young, hills and mountains successfully resist the destructive forces of nature.
　　○Although they seem permanent, hills and mountains exist for a relatively short period of geological time.
　　○Hills and mountains successfully resist the destructive forces of nature, but only for a short time.
　　○Hills and mountains resist the destructive forces of nature better than other types of landforms.
　　Paragraph 6: 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. 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. Even living things contribute to the formation 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 hold loose 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 to the 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 illustrate constructive processes and two are used to illustrate destructive processes. Complete the table by matching appropriate answer choices to the processes they are used to illustrate. This question is worth 3 points.
　　CONSTRUCTIVE PROCESSES  DESTRUCTIVE PROCESSSES
　　●
　　●
　　●
　　●
　　Answer Choices：
　　1.Collision of Earth's crustal plates
　　2.Separation of continents
　　3.Wind-driven sand
　　4.Formation of grass roots in soil
　　5.Earthquakes
　　6.Volcanic activity
　　7.Weather processes

　　參考答案：
　　1. ○ 4
　　This is a Factual Information question asking for specific information that can be found in paragraph 1. The correct answer is choice 4. Sentence 1 of the paragraph explicitly states that Earth's landscape changes relatively rapidly compared to Earth's overall age. Choice 1, on the frequency of landscape changes, is contradicted by the paragraph. Choice 2, that landscape changes occur only at special times, is also contradicted by the paragraph. Choice 3, the frequency 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 is comparing Earth's time scale to the human time scale, so "comparatively" is the correct answer.
　　3. ○ 2
　　This is an Inference question asking for an inference that can be supported by paragraph 2. The correct answer choice 2, the Himalayas arc higher than the Caledonian mountains. The paragraph states that younger mountains are general& higher than older mountains. It also states that the Himalayas are much younger than the Caledonians. Since the Himalayas are the younger range and Lounger mountain ranges are higher- than older ranges, we can infer that the younger Himalayas are higher than the older Caledonians.
　　Choices 1 and 4 are incorrect because that explicitly contradict the passage. The height of the Himalayas is an indication of their age, and the Himalayas are about the same height that the Caledonians were 400 million years ago. Choice 3 is incorrect because nothing there is nothing in the paragraph about "uniform height."
　　4. ○ 3
　　This is a Vocabulary question. The word being tested is relics, and it is highlighted in the passage. Choice 3 is the correct answer. The 1.e1ic.s of the Caledonian range are what is left of 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 in paragraph 3. The correct answer is choice 3, mountains are formed by crustal plates hitting each other. The paragraph states that mountains are formed in three ways: by, crustal plates hitting each other, by earthquakes, and by volcanoes. Choices 1,2, and 4 are not among these causes 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 the passage. This term is highlighted in the passage. The correct answer is choice 1; carbon dioxide is mentioned to explain the origin of a chemical that can erode rocks. The author is describing a particular 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 the passage. Choice 2, "Rows slowly," is the correct answer. The sentence is describing the way in which rain moves underground from Earth's surface. It cannot do this by "drying" (choice I), "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 the passage. Choice 2, "masses of ice" is the correct answer. This is a simple pronoun-referent item. The word tlze11z refers to the glaciers that are carrying eroded rock. Notice that in this case, 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 the passage is highlighted:
　　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.
　　The correct answer is choice 2. That choice contains all of the essential information in the highlighted sentence. it omits the information in the second clause of the highlighted sentence ("successfully resisting the destructive forces of nature") because that information is not essential to the meaning. Choices 1, 3, and 1 are all incorrect because they change the meaning of the highlighted sentence. Choice 1 adds information on the age of a mountain that is not mentioned in the highlighted sentence. Choice 3 introduces information about how long mountains resist forces of nature in absolute terms; the highlighted sentence says that the resistance is relatively short in geological terms, which is an entirely different meaning. Choice 4 compares mountains to other land forms. The highlighted sentence does not make any such comparison.
　　10. ○ 4
　　This is a Factual Information question asking for specific information that can be found in paragraph 6. The correct answer is choice 4, "sand." Sentences 3 and 4 of that paragraph describe erosion in dry areas. Sand is carried by wind and bombards rock; this bombardment breaks down the rock, and, as a result, more sand is created. Thus sand is both the cause and the 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 a result of erosion.
　　11. ○ 1
　　This is an Insert Text question. You can see the four black squares in paragraph 6 that represent the possible answer choices here.
　　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.  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. Even living things contribute to the formation 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 hold loose soil fragments together, thereby helping to prevent erosion by the wind.
　　The sentence provided, "Under different climatic conditions, another type of destructive force contributes to erosion,'' is best inserted at square 1.
　　Square 1 is correct because the inserted sentence is a transitional sentence, moving the discussion 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. No transition 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 for the "destructive processes" column. Choices 2 and 4 should not be used in either column.

　　參考譯文
　　大部分人認(rèn)為自然風(fēng)景是一成不變的，事實(shí)上地球是一個(gè)充滿活力的機(jī)體,他的外貌在人類文明進(jìn)程中一直保持著持續(xù)緩慢的變化。當(dāng)然，與大約4500億年前的冰河時(shí)代的地貌變化相比，這個(gè)進(jìn)程的確快了很多。主要有兩種影響會(huì)改變地形：建設(shè)性的過(guò)程，如產(chǎn)生新的地表特征的地殼隆起；和破壞性的力量，如緩慢清除突出地貌的地表侵蝕。
　　山峰和山脈因?yàn)槟軌蚪?jīng)受得住自然的洗禮，通常被認(rèn)作是永恒的代名詞，但地質(zhì)學(xué)的角度上來(lái)說(shuō)，他們的存在實(shí)際上從是相對(duì)比較短暫的。一般來(lái)說(shuō)，山峰越高，形成得越晚。例如喜馬拉雅山，她只有50萬(wàn)年的歷史。低矮山巒的歷史往往更加久遠(yuǎn)，它們通常是高聳的山脈崩塌后的遺留物。在大約400萬(wàn)年前，當(dāng)今天的北美和歐洲大陸相結(jié)合的時(shí)候，加勒多尼亞山脈與現(xiàn)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(yùn)動(dòng)）在今天遺留下來(lái)的卻只是相對(duì)非常低矮的格林蘭山脈：美國(guó)的北阿巴拉契亞山區(qū)，蘇格蘭高地和挪威海岸高原。
　　地殼分裂成為巨大可移動(dòng)的板塊，板塊在柔軟的巖石可塑層中漂移。有的時(shí)候，這些板塊互相沖擊并迫使板塊邊緣的巖石突起，從而形成山脈。在這個(gè)過(guò)程中，原本形成在海床上的沉積巖可能被拱起高達(dá)26，000多英尺。在另一種情況下，地震將地殼震裂。產(chǎn)生的巖石堆積形成斷塊山，從而形成山脈。還有一種情況，活火山帶的火山運(yùn)動(dòng)也會(huì)促使山脈的形成，例如北美洲西部的喀斯喀特山脈，他的產(chǎn)生就是由火山巖和火山灰形成的，上面的許多山峰都是死火山。
　　不論山脈形成的具體原因是什么，一旦陸地高出海平面，都難逃脫被外力摧毀的厄運(yùn)。裸露的巖石遭受著不斷變化天氣的攻擊，逐漸被碾成碎石塊帶走，然后形成沉積巖。因此，任何地貌都只是一個(gè)短暫的階段，它所代表的是造山與侵蝕兩種力量持續(xù)斗爭(zhēng)。
　　多種多樣的天氣加速了大自然對(duì)地貌的侵蝕。雨水沖刷了疏松的土壤并滲入到巖石的縫隙。二氧化碳在空氣中與雨水相互作用形成了可以對(duì)巖石進(jìn)行化學(xué)腐蝕的弱酸(碳酸)。雨水滲透到地下并能在不久后以泉水的形式流出，那些從巖石間穿過(guò)并將碎石從高山帶到平原的溪水就是來(lái)源于這些泉水。
　　在嚴(yán)寒的環(huán)境下，巖石能被冰霜粉碎。冰川在長(zhǎng)期寒冷的區(qū)域形成，這些緩慢移動(dòng)的大量冰塊帶著大量的腐蝕巖屑阻斷了山谷。在干旱地帶，風(fēng)是大自然侵蝕的主要手段。它帶著沙子中的微粒沖擊著裸露的巖石表面，把巖石吹散成更多的沙粒。動(dòng)植物們對(duì)自然風(fēng)景的形成也是功不可沒(méi)，大樹植根于巖縫之中，加速了巖石的碎裂。相比之下，草根和其他矮小植物則利于固定土壤，弱化了風(fēng)蝕作用的影響。