英語四級(jí)難度提升閱讀訓(xùn)練 Text 16

Text 16

Scattered around the globe are more than 100 small regions of isolated volcanic activity known to geologists as hot spots. Unlike most of the world's volcanoes, they are not always found at the boundaries of the great drifting plates that make up the earth's surface. On the contrary, many of them lie deep in the interior of a plate. Most of the hot spots move only slowly, and in some cases the movement of the plates past them has left trails of dead volcanoes. The hot spots and their volcanic trails are milestones that mark the passage of the plates.

That the plates are moving is not beyond dispute. Africa and South America, for example, are moving away from each other as new material is injected into the sea floor between them. The complementary coastlines and certain geological features that seem to span the ocean are reminders of where the two continents were once joined. The relative motion of the plates carrying these continents has been constructed in detail, but the motion of one plate with respect to another cannot readily be translated into motion with respect to the earth's interior. It is not possible to determine whether both continents are moving in opposite directions or whether one continent is stationary and the other is drifting away from it. Hot spots, anchored in the deeper layers of the earth, provide the measuring instruments needed to resolve the question. From an analysis of the hot spot population it appears that the African plate is stationary and that it has not moved during the past 30 million years.

The significance of hot spots is not confined to their role as a frame of reference. It now appears that they also have an important influence on the geophysical processes that propel the plates across the globe. When a continental plate come to rest over a hot spot, the material rising from deeper layer creates a broad dome. As the dome grows, it develops seed fissures (cracks); in at least a few cases the continent may break entirely along some of these fissures, so that the hot spot initiates the formation of a new ocean. Thus just as earlier theories have explained the mobility of the continents, so hot spots may explain their mutability (inconstancy).

1.The author believes that_______.

A.the motion of the plates corresponds to that of the earth's interior

B.the geological theory about drifting plates has been proved to be true

C.the hot spots and the plates move slowly in opposite directions

D.the movement of hot spots proves the continents are moving apart

2.That Africa and South America were once joined can be deduced from the fact that_______.

A.the two continents are still moving in opposite directions

B.they have been found to share certain geological features

C.the African plates has been stable for 30 million years

D.over 100 hot spots are scattered all around the globe

3.The hot spot theory may prove useful in explaining_______.

A.the structure of the African plates　B.the revival of dead volcanoes

C.the mobility of the continents　　　D.the formation of new oceans

4.The passage is mainly about_______.

A.the features of volcanic activities

B.the importance of the theory about drifting plates

C.the significance of hot spots in geophysical studies

D.the process of the formation of volcanoes

5.Which movement of the two continents is NOT mentioned in the article?

A.Two continents were joined.

B.One continent is stationary while other drifting.

C.Two continents move in reverse direction.

D.Two continents move in the same direction.

長(zhǎng)難例句分析

［長(zhǎng)難例句］Unlike most of the world's volcanoes, they are not always found at the boundaries of the great drifting plates that make up the earth's surface; on the contrary, many of them lie deep in the interior of a plate.

［結(jié)構(gòu)分析］本句話中，主干是they are not found... on the contrary... many of them lie。unlike引導(dǎo)的是狀語，由that引導(dǎo)的主語從句修飾the great drifting plates。on the contrary為連接詞，把兩個(gè)句子連接在一起。

［參考譯文］和大多數(shù)火山不同，它們都不位于形成地球表面的巨大漂移板塊的連接點(diǎn)，反而有很多藏于板塊的深處。

全文參考譯文

地球上零碎分布著一百多個(gè)相互獨(dú)立并且面積不大的火山活動(dòng)區(qū)，地質(zhì)學(xué)家稱之為“熱點(diǎn)區(qū)”。和大多數(shù)火山不同，它們都不位于形成地球表面的巨大漂移板塊的連接點(diǎn)，反而有很多藏于板塊的深處。大部分熱點(diǎn)區(qū)移動(dòng)極其緩慢，有時(shí)候，板塊滑過這些熱點(diǎn)區(qū)，便留下死火山的痕跡。熱點(diǎn)區(qū)加上其火山痕跡是板塊移動(dòng)的象征。

板塊漂移學(xué)說如今已是無需質(zhì)疑的了。例如非洲和南美洲，因?yàn)橛行挛镔|(zhì)深入洋底，兩個(gè)大陸距離愈來愈遠(yuǎn)。即使遠(yuǎn)隔大洋，可相互吻合的海岸線和似乎好像跨越過海的地質(zhì)特征，均會(huì)讓人想到這兩個(gè)大陸曾是相連的。帶著兩個(gè)大陸漂移的板塊做相對(duì)運(yùn)動(dòng)，這已得到具體解釋，但不能把一個(gè)板塊相對(duì)于另一板塊的運(yùn)動(dòng)簡(jiǎn)單地解釋為板塊與地球內(nèi)部之間的運(yùn)動(dòng)。由于人們還沒法肯定兩個(gè)大陸是否在朝相反的方向運(yùn)動(dòng)，也沒法肯定是否是一個(gè)大陸原地不動(dòng)，而另一個(gè)大陸正在遠(yuǎn)離它而去。因而位于地殼深處的熱點(diǎn)區(qū)提供了解決這一問題的測(cè)量?jī)x。從熱點(diǎn)區(qū)的人口情況分析顯示，好像非洲板塊是不動(dòng)的，3000萬年過去了也沒見移動(dòng)。

熱點(diǎn)區(qū)的重要意義并不僅僅只是它們所起到的參照物的作用。如今它們還對(duì)推動(dòng)板塊在地球表面漂移這一地球物理進(jìn)程有重要作用。當(dāng)大陸板塊漂移到熱點(diǎn)區(qū)上方時(shí)，由地殼深處涌出的物質(zhì)便會(huì)使板塊凸起，形成巨大圓蓋。圓蓋不斷裂大，板塊出現(xiàn)深深的裂痕。至少有幾次，大陸差點(diǎn)順著這些裂痕完全分開。因而，熱點(diǎn)區(qū)理論解釋了新海洋的起因。這樣一來，就像早些時(shí)候的一些理論已經(jīng)解釋了大陸的流動(dòng)性一樣，熱點(diǎn)區(qū)理論或許能對(duì)大陸板塊的不穩(wěn)定性加以說明。

題目答案與解析

1.作者相信，________。

A.板塊的運(yùn)動(dòng)與地球內(nèi)部的運(yùn)動(dòng)相似

B.有關(guān)板塊漂移的地質(zhì)理論已經(jīng)被證實(shí)是正確的

C.熱點(diǎn)與板塊向相反的方向緩慢移動(dòng)

D.熱點(diǎn)的運(yùn)動(dòng)證明大陸正在逐漸分離

【答案】B

【解析】從文章第一段的內(nèi)容可知，地球上散布著一百多個(gè)熱點(diǎn)；大多數(shù)的熱點(diǎn)獨(dú)自緩慢運(yùn)動(dòng)，某些情況下，經(jīng)過這些熱點(diǎn)的板塊運(yùn)動(dòng)留下死火山的痕跡；熱點(diǎn)及其火山痕跡是標(biāo)志板塊遷移的符號(hào)；從文章第二段的內(nèi)容可知，如今，有關(guān)板塊在運(yùn)動(dòng)的理論已經(jīng)無可爭(zhēng)辯；然后舉例進(jìn)一步說明；從文章最后一段的內(nèi)容可知，熱點(diǎn)的重要性并不僅限于作為參照體系這一作用上；現(xiàn)在看來，它們對(duì)推動(dòng)板塊在地球上移動(dòng)的地球物理學(xué)的過程也產(chǎn)生了重大影響；因此，正如早期的理論解釋了大陸的移動(dòng)那樣，熱點(diǎn)或許可以解釋大陸的不穩(wěn)定性。據(jù)此可知，作者認(rèn)為有關(guān)大陸移動(dòng)的理論是正確的。B項(xiàng)文中的意思相符，因此為正確答案。

2.推論出非洲和南美洲曾經(jīng)連在一起，可以依據(jù)________。

A.這兩個(gè)洲仍然在向相反的方向移動(dòng)　B.人們發(fā)現(xiàn)，這兩個(gè)洲具有引人注目的地質(zhì)特征

C.非洲板塊已經(jīng)穩(wěn)定了3000萬年　　　D.地球各地散布著一百多個(gè)熱點(diǎn)

【答案】B

【解析】本題可參照文章的第二段。從中可知，由于新物質(zhì)被增添進(jìn)非洲和南美洲之間的海底，因此這兩個(gè)洲正在逐漸分離；相吻合的海岸線以及似乎橫跨海洋的地質(zhì)特征提示人們——這兩塊大陸曾經(jīng)連接在一起。據(jù)此可知，人們之所以認(rèn)為非洲和南美洲曾經(jīng)連在一起，是因?yàn)樗鼈兊哪承┑刭|(zhì)特征相似。B項(xiàng)與文中的意思相符，因此為正確答案。

3.熱點(diǎn)理論在解釋_______時(shí)可能被證實(shí)有用。

A.非洲板塊的結(jié)構(gòu)　B.死火山的復(fù)活

C.大陸的漂移　　　D.新海洋的形成

【答案】D

【解析】本題可參照文章的第三段。從中可知，熱點(diǎn)的重要性并不僅限于作為參照體系這一作用上；現(xiàn)在看來，它們對(duì)推動(dòng)板塊在地球上移動(dòng)的地球物理學(xué)的過程也產(chǎn)生了重大影響；當(dāng)一個(gè)大陸性板塊在一個(gè)熱點(diǎn)上停止移動(dòng)時(shí)，從地球更深層涌出的物質(zhì)會(huì)形成一個(gè)巨大的圓丘；隨著圓丘不斷增長(zhǎng)，它會(huì)出現(xiàn)深深的裂溝；在某些情況下，大陸至少可能會(huì)沿著這樣的一些裂縫完全分裂，于是，該熱點(diǎn)便開始形成一個(gè)新海洋；因此，正如早期的理論解釋了大陸的移動(dòng)那樣，熱點(diǎn)或許可以解釋大陸的不穩(wěn)定性。據(jù)此可知，熱點(diǎn)理論可以用于解釋大陸的不穩(wěn)定性，即熱點(diǎn)可以促使形成新海洋。D項(xiàng)與文章的意思相符，因此為正確答案。

4.本篇文章主要是關(guān)于________。

A.火山運(yùn)動(dòng)的特點(diǎn)　　　　　　　B.有關(guān)板塊漂移理論的重要性

C.地質(zhì)物理研究中熱點(diǎn)的重要性　D.火山形成的過程

【答案】C

【解析】從文章第一段的內(nèi)容可知，地球上散布著一百多個(gè)與外部隔絕的火山活動(dòng)小區(qū)域，地質(zhì)學(xué)家稱之為熱點(diǎn)；隨后說明了熱點(diǎn)的特點(diǎn)；文章第二段說明了板塊漂移理論，最后一句話指出：根據(jù)熱點(diǎn)密度的分析可以看出——非洲板塊靜止不動(dòng)了3000萬年；從文章第三段的內(nèi)容可知，熱點(diǎn)的重要性并不僅限于作為參照體系這一作用上，它們對(duì)推動(dòng)板塊地球上移動(dòng)的地質(zhì)物理過程也產(chǎn)生了重大影響；然后具體說明了熱點(diǎn)如何促使形成了新海洋；從文章的最后一句話可知，正如早期的理論解釋了大陸的移動(dòng)那樣，熱點(diǎn)理論或許可以解釋大陸的易變性。據(jù)此可知，本文主要講的是熱點(diǎn)理論在地質(zhì)物理研究中的重要作用。C項(xiàng)與文章的意思相符，因此為正確答案。

5.對(duì)于兩個(gè)大陸之間的運(yùn)動(dòng)關(guān)系，文中沒有提及是哪一個(gè)？

A.兩個(gè)大陸連接起來?！.一個(gè)大陸固定不動(dòng)，另一個(gè)大陸在漂移。

C.兩個(gè)大陸背向漂移?！.兩個(gè)大陸相向漂移。

【答案】D

【解析】本題考查對(duì)細(xì)節(jié)的理解。全文中沒有提到大陸板塊相撞的話題。