TPO是托福备考圣经，但是并不是有“圣经”就能完全把握托福考试。还要看大家怎么去利用这份资料。针对原文，我们可以最大限度的剖析再剖析。直到把文章掌握得滚瓜烂熟。而大家又是怎样对待其中的每个考题呢？是做完对对答案，记下答对率；还是认真分析每个考题在考什么，找出托福阅读的“点”在哪？前者居多吧！
所以关于托福阅读TPO，小编希望最大限度地利用这些ETS提供的阅读题目。在题目中，找到每个题目考察点，给出最全最有逻辑的解析。今天，小编分享给大家的是关于TPO1 Timberline Vegetation on Mountains的题目分析。
Timberline Vegetation on Mountains
山上树带界线的植被
1.The transition from forest to treeless tundra on a mountain slope is often a dramatic one. Within a vertical distance of just a few tens of meters, trees disappear as a life-form and are replaced by low shrubs, herbs, and grasses. This rapid zone of transition is called the upper timberline or tree line. In many semiarid areas there is also a lower timberline where the forest passes into steppe or desert at its lower edge, usually because of a lack of moisture.
2.The upper timberline, like the snow line, is highest in the tropics and lowest in the Polar Regions. It ranges from sea level in the Polar Regions to 4,500 meters in the dry subtropics and 3,500-4,500 meters in the moist tropics. Timberline trees are normally evergreens, suggesting that these have some advantage over deciduous trees (those that lose their leaves) in the extreme environments of the upper timberline. There are some areas, however, where broadleaf deciduous trees form the timberline. Species of birch, for example, may occur at the timberline in parts of the Himalayas.
3.At the upper timberline the trees begin to become twisted and deformed. This is particularly true for trees in the middle and upper latitudes, which tend to attain greater heights on ridges, whereas in the tropics the trees reach their greater heights in the valleys. This is because middle- and upper- latitude timberlines are strongly influenced by the duration and depth of the snow cover. As the snow is deeper and lasts longer in the valleys, trees tend to attain greater heights on the ridges, even though they are more exposed to high-velocity winds and poor, thin soils there. In the tropics, the valleys appear to be more favorable because they are less prone to dry out, they have less frost, and they have deeper soils.
4.There is still no universally agreed-on explanation for why there should be such a dramatic cessation of tree growth at the upper timberline. Various environmental factors may play a role. Too much snow, for example, can smother trees, and avalanches and snow creep can damage or destroy them. Late-lying snow reduces the effective growing season to the point where seedlings cannot establish themselves. Wind velocity also increases with altitude and may cause serious stress for trees, as is made evident by the deformed shapes at high altitudes. Some scientists have proposed that the presence of increasing levels of ultraviolet light with elevation may play a role, while browsing and grazing animals like the ibex may be another contributing factor. Probably the most important environmental factor is temperature, for if the growing season is too short and temperatures are too low, tree shoots and buds cannot mature sufficiently to survive the winter months.
5.Above the tree line there is a zone that is generally called alpine tundra. Immediately adjacent to the timberline, the tundra consists of a fairly complete cover of low-lying shrubs, herbs, and grasses, while higher up the number and diversity of species decrease until there is much bare ground with occasional mosses and lichens and some prostrate cushion plants. Some plants can even survive in favorable microhabitats above the snow line. The highest plants in the world occur at around 6,100 meters on Makalu in the Himalayas. At this great height, rocks, warmed by the sun, melt small snowdrifts.
6.The most striking characteristic of the plants of the alpine zone is their low growth form. This enables them to avoid the worst rigors of high winds and permits them to make use of the higher temperatures immediately adjacent to the ground surface. In an area where low temperatures are limiting to life, the importance of the additional heat near the surface is crucial. The low growth form can also permit the plants to take advantage of the insulation provided by a winter snow cover. In the equatorial mountains the low growth form is less prevalent.
阅读题目在这里
Paragraph 1: The transition from forest to treeless tundra on a mountain slope is often a dramatic one. Within a vertical distance of just a few tens of meters, trees disappear as a life-form and are replaced by low shrubs, herbs, and grasses. This rapid zone of transition is called the upper timberline or tree line. In many semiarid areas there is also a lower timberline where the forest passes into steppe or desert at its lower edge, usually because of a lack of moisture.
1. The word “dramatic” in the passage is closest in meaning to
○gradual
○complex
○visible
○striking
解析：答案是(4)。相关句Within a vertical distance of just a few tens of meters, trees disappear as a life-form and are replaced by low shrubs, herbs, and grasses. 在一个垂直距离只有几十米的地方，树木这种生命形式就消失了，取而代之的是低矮的灌木、草本植物和牧草。这句话是对前一句的解释句。所以看出transition是很明显，变化很大的。
考察点：句子之间的逻辑。
2. Where is the lower timberline mentioned in paragraph 1 likely to be found?
○In an area that has little water
○In an area that has little sunlight
○Above a transition area
○On a mountain that has on upper timberline.
解析：答案是(1)
由lower timberline定位到到段落最后一句话“In many semiarid areas there is also a lower timberline where the forest passes into steppe or desert at its lower edge, usually because of a lack of moisture.”意思是：在很多半干旱地区有一个下树届带，在那里的低边界树变成草原或荒漠，通常是因为缺乏水分。
考察点：因果句。
3. Which of the following can be inferred from paragraph 1 about both the upper and lower timberlines?
○Both are treeless zones.
○Both mark forest boundaries.
○Both are surrounded by desert areas.
○Both suffer from a lack of moisture.
解析：答案是(2)
从这些句子中找答案：This rapid zone of transition is called the upper timberline or tree line. In many semiarid areas there is also a lower timberline where the forest passes into steppe or desert at its lower edge, usually because of a lack of moisture.所以二者都有“变化“。属于一个分界。
考察点：一些对比或者also这样的提示词。
Paragraph 2: The upper timberline, like the snow line, is highest in the tropics and lowest in the Polar Regions. It ranges from sea level in the Polar Regions to 4,500 meters in the dry subtropics and 3,500-4,500 meters in the moist tropics. Timberline trees are normally evergreens, suggesting that these have some advantage over deciduous trees (those that lose their leaves) in the extreme environments of the upper timberline. There are some areas, however, where broadleaf deciduous trees form the timberline. Species of birch, for example, may occur at the timberline in parts of the Himalayas.
4. Paragraph 2 supports which of the following statements about deciduous trees?
○They cannot grow in cold climates.
○They do not exist at the upper timberline.
○They are less likely than evergreens to survive at the upper timberline.
○They do not require as much moisture as evergreens do.
解析：答案是(3)
段落第三句话“Timberline trees are normally evergreens, suggesting that these have some advantage over deciduous trees(those that lose their leaves) in the extreme environments of the upper timberline.”意思是：树届带的树通常都是常青树，这意味着这些树比落叶树在上树届带极端环境中生存更有优势。Normally adv.通常情况；deciduous adj.每年落叶的；
考察点：对于这种ETS“不打自招“的解释信息，这里一定会出题。(those that lose their leaves)
Paragraph 3: At the upper timberline the trees begin to become twisted and deformed. This is particularly true for trees in the middle and upper latitudes, which tend to attain greater heights on ridges, whereas in the tropics the trees reach their greater heights in the valleys. This is because middle- and upper- latitude timberlines are strongly influenced by the duration and depth of the snow cover. As the snow is deeper and lasts longer in the valleys, trees tend to attain greater heights on the ridges, even though they are more exposed to high-velocity winds and poor, thin soils there. In the tropics, the valleys appear to be more favorable because they are less prone to dry out, they have less frost, and they have deeper soils.
5. The word “attain” in the passage is closest in meaning to
○require
○resist
○achieve
○endure
解析：答案是(3)
which tend to attain greater heights on ridges, whereas in the tropics the trees reach their greater heights in the valleys. 对比或者并列情况下都可以找到同义替换，这里是reach
考察点：对比意味的地方有考点同义替换。
6. The word “they” in the passage refers to
○valleys
○trees
○heights
○ridges
解析：答案是(2) As the snow is deeper and lasts longer in the valleys, trees tend to attain greater heights on the ridges, even though they are more exposed to high-velocity winds and poor, thin soils there.要考虑逻辑。
考点；代词还原。
7. The word “prone” in the passage is closest in meaning to
○adapted
○likely
○difficult
○resistant
解析：答案是(2)
In the tropics, the valleys appear to be more favorable because they are less prone to dry out, they have less frost, and they have deeper soils.
首先说一下，有些解析会说“查字典知道答案是…”真心醉了……
less prone，这里有比较级，所以找和谁再比可以找到前面，even though they are more exposed to high-velocity winds and poor, thin soils there.正好more exposed to与之对应。“更不易，更少可能这一类的意思”。
考点：比较级。
8. According to paragraph 3, which of the following is true of trees in the middle and upper latitudes?
○Tree growth is negatively affected by the snow cover in valleys
○Tree growth is greater in valleys than on ridges.
○Tree growth on ridges is not affected by high-velocity winds.
○Tree growth lasts longer in those latitudes than it does in the tropics.
解析：答案是(1)
回到段落第三句“This is because middle-and upper- altitude timberlines are strongly influenced by the duration and depth of the snow cover.”意思是：这是因为中高纬度的树届带强烈受到雪覆盖长度和深度的影响。第四句“As the snow is deeper and lasts longer in the valleys, trees tend to attain greater heights on the ridges, even though they are more exposed to high-velocity winds and poor, thin soils there.”意思是：因为雪在山谷更深持续时间更长，树在山脊上达到的高度更高，尽管它们更会被暴露在高速风和贫瘠薄弱土壤中。选项二，三都错了。段落最后一句：In the tropics, the valleys appear to be more favorable because they are less prone to dry out, they have less frost, and they have deeper soils. 意思是：在热带，山谷更适宜生长因为它们不会那么容易干涸，其中霜更少，并且泥土更深。所以选项四错。
考点：应该也是有两个事物并列、对比是易出题吧!
Paragraph 4：There is still no universally agreed-on explanation for why there should be such a dramatic cessation of tree growth at the upper timberline. Various environmental factors may play a role. Too much snow, for example, can smother trees, and avalanches and snow creep can damage or destroy them. Late-lying snow reduces the effective growing season to the point where seedlings cannot establish themselves. Wind velocity also increases with altitude and may cause serious stress for trees, as is made evident by the deformed shapes at high altitudes. Some scientists have proposed that the presence of increasing levels of ultraviolet light with elevation may play a role, while browsing and grazing animals like the ibex may be another contributing factor. Probably the most important environmental factor is temperature, for if the growing season is too short and temperatures are too low, tree shoots and buds cannot mature sufficiently to survive the winter months.
9. Which of the sentences below best express the essential information in the highlighted sentence in the passage? In correct choices change the meaning in important ways or leave out essential information.
○Because of their deformed shapes at high altitudes, trees are not likely to be seriously harmed by the strong winds typical of those altitudes.
○As altitude increases, the velocity of winds increase, leading to a serious decrease in the number of trees found at high altitudes.
○The deformed shapes of trees at high altitudes show that wind velocity, which increase with altitude, can cause serious hardship for trees.
○Increased wind velocity at high altitudes deforms the shapes of trees, and this may cause serious stress for trees.
解析：答案是(3)
原句Wind velocity also increases with altitude and may cause serious stress for trees, as is made evident by the deformed shapes at high altitudes
原句结构：动作a increases +动作b cause，有证据。看看哪个最接近就好了。
考点：长难句。
10. In paragraph 4, what is the author’s main purpose in the discussion of the dramatic cessation of tree growth at the upper timberline?
○To argue that none of several environment factors that are believed to contribute to that phenomenon do in fact play a role in causing it.
○To argue in support of one particular explanation of that phenomenon against several competing explanations
○To explain why the primary environmental factor responsible for that phenomenon has not yet been identified
○To present several environmental factors that may contribute to a satisfactory explanation of that phenomenon
解析：答案是(4)
回到段落看第一句“There is still no universally agreed-on explanation for why there should be such a dramatic cessation of tree growth at the upper timberline.”意思是：对于为什么树在上树届带戏剧性的停止生长还没有一个普遍同意的解释。再看接下一句“Various environmental factors may play a role.”各种不同的环境因素都可能起到作用。而整个自然段之后就进一步描述了那几个自然环境因素。
考点：段落结构。一般还是那些结构清晰的段落。
Paragraph 6: The most striking characteristic of the plants of the alpine zone is their low growth form. This enables them to avoid the worst rigors of high winds and permits them to make use of the higher temperatures immediately adjacent to the ground surface. In an area where low temperatures are limiting to life, the importance of the additional heat near the surface is crucial. The low growth form can also permit the plants to take advantage of the insulation provided by a winter snow cover. In the equatorial mountains the low growth form is less prevalent.
11. The word “prevalent” in the passage is closest in meaning to
○predictable
○widespread
○successful
○developed
解析：答案是(2)
less prevalent.找到和谁在比较，找到In an area where low temperatures are limiting to life, the importance of the additional heat near the surface is crucial. The low growth form can also permit the plants to take advantage of the insulation provided by a winter snow cover. In the equatorial mountains the low growth form is less prevalent.
有对比，前面的高山地带上，这种树木形式可以利用……但赤道附近就该没那么……了，应该表现出没那么多，没那么广之类的意思。
考点：比较级。
12. According to paragraph 6, all of the following statements are true of plants in the alpine zone EXCEPT:
○Because they are low, they are less exposed to strong winds.
○Because they are low, the winter snow cover gives them more protection from the extreme cold.
○In the equatorial mountains, they tend to be lower than in mountains elsewhere.
○Their low growth form keeps them closer to the ground, where there is more heat than further up
解析：答案是(3)
原文段落最后一句“In the equatorial mountains the low growth form is less prevalent.”意思是：在赤道山区，这种低生长形式更少。选项三与其矛盾了。
“The most striking characteristic of the plants of the alpine zone is their low growth form. This enables them to avoid the worst rigors of high winds and permits them to make use of the higher temperatures immediately adjacent to the ground surface. 意思是：在高山带植物的低增长形式是最引人注目的特点。这一特点使它们能够避免最强劲苛刻的风力并且让它们利用靠近地表的高温。所以选项一，四都对；段落倒数第二句“The low growth form can also permit the plants to take advantage of the insulation provided by a winter snow cover.”意思是：这种低生长形式还使植物能够利用冬天覆雪的隔热。所以选项二正确。
考点：有比较的地方易出题。
Paragraph 5: Above the tree line there is a zone that is generally called alpine tundra. █Immediately adjacent to the timberline, the tundra consists of a fairly complete cover of low-lying shrubs, herbs, and grasses, while higher up the number and diversity of species decrease until there is much bare ground with occasional mosses and lichens and some prostrate cushion plants. █Some plants can even survive in favorable microhabitats above the snow line. The highest plants in the world occur at around 6,100 meters on Makalu in the Himalayas. █At this great height, rocks, warmed by the sun, melt small snowdrifts. █
13. Look at the four squares [█] that indicate where the following sentence could be added to the passage.
This explains how, for example, alpine cushion plants have been found growing at an altitude of 6,180 meters.
Where would the sentence best fit?
解析：答案是(4)
This，explains,前面一句是个关于alpine cushion plants生长在很高海拔的解释。只有最后一句话是一个解释“At this great height, rocks, warmed by the sun, melt small snowdrifts. ”意思是：在这样大的高度上，受到太阳的温暖，融化了小雪堆。
考点：句间逻辑。
14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
At the timberline, whether upper or lower, there is a profound change in the growth of trees and other plants.
Answer choices
○Birch is one of the few species of tree that can survive in the extreme environments of the upper timberline.
○There is no agreement among scientists as to exactly why plant growth is sharply different above and below the upper timberline.
○The temperature at the upper timberline is probably more important in preventing tree growth than factors such as the amount of snowfall or the force of winds.
○The geographical location of an upper timberline has an impact on both the types of trees found there and their physical characteristics.
○High levels of ultraviolet light most likely play a greater role in determining tree growth at the upper timberline than do grazing animals such as the ibex.
○Despite being adjacent to the timberline, the alpine tundra is an area where certain kinds of low trees can endure high winds and very low temperatures.
解析：答案是(2)(4)(6)
选项一错，这是一个细节，不符合文章论述主体。
选项二对，文章第四段主题句。
选项三错，文章第四段中没有这样的比较。
选项四对，文章第二段讲了树的类型，第三段讲了树变形。
选项五错，文章第四段没有这个比较。
选项六对，文章第五，六段的主要内容。
以上就是要分享给大家的关于TPO1-1 Timberline Vegetation on Mountains的解析及做题需要注意的问题，希望本文的内容能够帮助大家备考，前程百利祝大家都能取得理想的托福考试成绩。
您还可能关注：
