tpo27阅读答案及解析
tpo27阅读原文
【3】How can volcanic activity occur so far from a plate boundary? The Hawaiian Islands provide a very instructive answer. Like many other island groups, they form a chain. The Hawaiian Islands Chain extends northwest from the island of Hawaii. In the 1840s American geologist James Daly observed that the different Hawaii islands seem to share a similar geologic evolution but are progressively more eroded, and therefore probable older, toward the northwest.Then in 1963, in the early days of the development of the theory of plate tectonics. Canadian geophysicist Tuzo Wilson realized that this age progression could result if the islands were formed on a surface plate moving over a fixed volcanic source in the interior. Wilson suggested that the long chain of volcanoes stretching northwest from Hawaii is simply the surface expression of a long-lived volcanic source located beneath the tectonic plate in the mantle. Today’s most northwest island would have been the first to form. They as the plate moved slowly northwest, new volcanic islands would have forms as the plate moved over the volcanic source. The most recent island, Hawaii, would be at the end of the chain and is now over the volcanic source.
【4】Although this idea was not immediately accepted, the dating of lavas in the Hawaii (and other) chains showed that their ages increase away from the presently active volcano, just as Daly had suggested. Wilson’s analysis of these data is now a central part of plate tectonics. Most volcanoes that occur in the interiors of plates are believed to be produced by mantle plumes, columns of molten rock that rise from deep within the mantle. A volcano remains an active “hot spot” as long as it is over the plume. The plumes apparently originate at great depths, perhaps as deep as the boundary between the core and the mantle, and many have been active for a very long time. The oldest volcanoes in the Hawaii hot-spot trail have ages close to 80 million years. Other islands, including Tahiti and Easter Islands in the pacific, Reunion and Mauritius in the India Ocean, and indeed most of the large islands in the world’s oceans, owe their existence to mantle plumes.
【5】The oceanic volcanic islands and their hot-spot trails are thus especially useful for geologist because they record the past locations of the plate over a fixed source. They therefore permit the reconstruction of the process of seafloor spreading, and consequently of the geography of continents and of ocean basins in the past. For example, given the current position of the Pacific Plate, Hawaii is above the Pacific Ocean hot spot. So the position of The Pacific Plate 50 million years ago can be determined by moving it such that a 50-million-year-oil volcano in the hot-spot trail sits at the location of Hawaii today. However because the ocean basins really are short-lived features on geologic times scale, reconstruction the world’s geography by backtracking along the hotspot trail works only for the last 5 percent or so of geologic time.
tpo27阅读实试题
1.The author mentions “spreading ridges”, “subduction zones”, and“transform faults” in order to
A.illustrate that the boundaries of tectonic plates are neat, thin lines.
B.explain why some tectonic plates carry islands or continents while others form the seafloor.
C.explain the complex nature of the edges of tectonic plates.
D.provide examples of areas of tectonic plates where little geologic action occurs.
2.The word “converge” in the passage is closest in meaning to
A.expand.
B.form.
C.rise.
D.move closer.
3.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage paragraph 2 ? Incorrect choices change the meaning in important ways or leave out essential information
A.Volcanic activity is responsible for the formation of the Pacific seafloor in the interior of the Pacific Plate.
B.Many volcanoes in the Pacific Ocean are no longer active and have become islands that support coral.
C.There are many islands in the Pacific Ocean that originated as volcanoes in the interior of the Pacific Plate.
D.The map of the Pacific Ocean reveals fewer volcanic islands than there truly are because many are no longer active and some are completely overgrown with coral.
4.The word “instructive” in the passage(paragraph 3)is closest in meaning to
A.clear.
B.detailed.
C.informative.
D.familiar.
5.The word “eroded” in the passage(paragraph 3)is closest in meaning to
A.worm down.
B.scattered.
C.developed.
D.deserted.
6.In paragraph 3, what is the relationship between the scientific contribution of James Daly and Tuzo Wilson?
A.Wilson provided an explanation for the observations made by Daly.
B.Wilson challenged the theory proposed by Daly.
C.Wilson found numerous examples of island chains that supported Daly’s theory.
D.Wilson popularized the explanation of volcanic island formation formulated by Daly.
7.Why does the author provide the information that “the dating of lavas in the Hawaii (and other) chains showedthat their ages increase away from the presently active volcano”?
A.To point out differences between the Hawaii island chain and other volcanic island chains.
B.To question the idea that all the islands in an island chain have been formed by volcanic activity.
C.To explain why Wilson hypothesis was initially difficult to accept.
D.To provide evidence in support of Daly’s and Wilson’s ideas about how the Hawaii islands were formed.
8.According to paragraph 4, which of the following is true of mantleplumes?
A.They exist close to the surface of tectonic plates.
B.They cause most of the volcanic activity that occurs in the interiors of plates.
C.They are rarely active for long period of time.
D.They get increasingly older away from the present hot spots.
9.According to paragraph 5, volcanic islands help geologists to
A.reconstruct past geography.
B.detect changes in mantle plumes.
C.measure the rigidity of tectonic plates.
D.explain why the seafloor spreads.
10.What can be inferred about the Pacific Plate from paragraph 5?
A.The hot spots on the Pacific Plate are much older than the ones located on the other tectonic plates.
B.Most of the volcanic sources beneath the Pacific Plate have become extinct.
C.The Pacific Plate has moved a distance equal to the length of the Hawaiian Island chain in the past 80 million years.
D.The Pacific Plate is located above fewer mantle plumes than other plates are.
11.The word “current” in the passage(paragraph 5)is closest in meaning to
A.original.
B.ideal.
C.relative.
D.present.
12.According to paragraph 5, why are geologists unable to trace back theentire geologic of continents from hot-spot trails?
A.Hot spots have existed for only about 5 percent of geologic time.
B.Hawaii did not exist 50 millions years ago.
C.Oceanic basins that contained old hot-spot trails disappeared a long time ago.
D.Hot-spot trails can be reconstructed only for island chains.
13. Look at the four squares [■] that indicate where the following sentence could be added to the passage. Where would the sentence best fit? This pattern remained unexplained for a long time.
How can volcanic activity occur so far from a plate boundary? The Hawaiian islands provide a very instructive answer. ■【A】Like many other island groups, they form a chain. ■【B】The Hawaiian Islands Chain extends northwest from the island of Hawaii. ■【C】In the 1840s American geologist James Daly observed that the different Hawaii islands seem to share a similar geologic evolution but are progressively more eroded, and therefore probable older,toward the northwest. ■【D】Then in 1963, in the early days of the development of the theory of plate tectonics. Canadian geophysicist Tuzo Wilson realized that this age progression could result if the islands were formed on a surface plate moving over a fixed volcanic source in the interior. Wilson suggested that the long chain of volcanoes stretching northwest from Hawaii is simply the surface expression of a long-lived volcanic source located beneath the tectonic plate in the mantle. Today’s most northwest island would have been the first to form. They as the plate moved slowly northwest, new volcanic islands would have forms as the plate moved over the volcanic source. The most recent island, Hawaii, would be at the end of the chain and is now over the volcanic source.
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.
Although volcanic activity is concentrated on the edge of tectonicplates, such activity can occur in the interiors of plates as well.
A.Our understanding of islands comes from Daly’s and Wilson’s observations of the Hawaiian Islands, which was later confirmed by plate-tectonic theory.
B.The hot-spot trails formed by volcanic island chains indicate the positions of tectonic plates as for back as the present ocean basins have existed.
C.Whereas volcanic islands formed by mantle plumes are typically small, most of the world’s largest islands are formed at the edges of tectonic plates.
D.It has only recently been discovered that tectonic plates are closely fitting rather than loosely constructed, as geologist previously believed.
E.Volcanic island chains such as the Hawaiian Islands form in the interior of a tectonic plate as the plate moves over a fixed volcanic source in the mantle.
F.The Pacific Plate has existed for as long as the Hawaiian Islands have existed, namely for more than 80 million years.
tpo27阅读答案及解析
1.原文这部分介绍了各种不同的edges的现象，并做了详细的解释，前面也说到plate的组成就像是jigsaw puzzle，从两处可以看出应该是要体现其复杂性。A与原文矛盾，原文并没有对B做出解释，D原文给出的是geologic action常发的地方，而不是little ~ occurs。
2.这一段描述的前两种现象，一种是move closer，一种是move apart。对第三种的描写是neither…nor…既不也不，因此应该是与前两种都不同，所以应该是既不聚合，也不分开，根据词根可以判断diverge是分开，converge是聚合。所以答案为D。
3.根据这一段的第一句可以看出后面是在举例说内陆平静的exception。A，B，D选项都是句子的细节部分，不能表达出其目的。所以不选。
4.instructive是有意义的，教育性的。 A是清楚的，B是细节的，D是熟悉的。只有C是有益的，教育性的，意思吻合。前面是问句，后面说夏威夷群岛提供了怎样的解答，那么应该是这个例子可以回答这个问题。根据这层意思，可以推出答案。
5.这句话说不同的岛屿看起来经历了相似的演变过程，但有些随着时间推移被更……，所以可能更古老。那么岛屿如果经历的时间更长应该会被海水“侵蚀”的更厉害。所以答案选A，worn down 磨损。 B是分散的，C是发达的，成熟的;D是被遗弃的。
6.根据两个科学家的名字进行定位。从then in 1963这一句可以了解到两者关系，说在板块理论刚开始发展的时期，tuzo Wilson发现……那么肯定是使板块理论进一步发展了。所以B不对。而C虽然逻辑关系对，但文中只给了夏威夷岛一个例子。所以C不选。D说使解释流行，之前daly只是给了理论，并没解释，所以不对。而A既符合逻辑关系，也对wilson的描写是正确的。
7.这个题很简单啦，往后面再多看一点点就知道答案啦。Just as Daly had suggested。
8.根据mantle plumes定位，可定位地第一句(已用红色标出)就说了它是导致板块内部火山爆发的原因，往后读可以看到它首先是起源于很深的地方，其次活动时间很长。因此A，C，D都不对。所以正确答案为B。
9.定位到这一段的第二句。D选项虽然也对，但是A可以包括D。
10.定位到for example，定位句几乎就是选项C的原义转换啦。A，B，D原文都没提到。
11.current是现在的意思。A是原始的，B是理想的，C是相对的，D是现在的。根据原句中也可以判断，因为后文说，通过大平洋板块什么的位置，可以判断其5千万年前的位置，那么两者应该是相反的。所以答案为D。
12.定位到最后一句。说不能追踪到整个变化过程是因为海洋盆地的变化相对比较快。
13.D的位置前面提到了大陆版块构造论，但并没给出解释，后半部分给出了很多年后另一位科学家给出的解释。
14.A正确 整篇文章都在说这个。。。一直是在说夏威夷岛的火山现象证明了大陆板块构造理论呀。B错误，不选。这个老早就发现了吧，当初daly提出的时候就说的是closely fitting的呀。C正确，对应文章最后一段的橘黄色标出部分。D正确，对应文章第二段红色标出部分。E错误，不选。文章没提到这些火山小。F错误。文章最后一段说到ocean basin是相对短暂的存在。并没有存在超过8千万年。