An important environment that is more or less totallyrestrictedto the intertropicalzoneis thecoralreef. Coralreefs are found where the ocean watertemperatureis not less than 21 °C, where there is afirmsubstratum, and where the seawater is not rendered too dark byexcessiveamounts of river-bornesediment. They will not grow in very deep water, so a platform within 30 to 40 meters of the surface is a necessaryprerequisitefor theirdevelopment. Theirphysicalstructure is dominated by the skeletons of corals, which arecarnivorousanimals living offzooplankton. However, inadditionto corals there areenormousquantities ofalgae, somecalcareous, which help to build the reefs. The size of reefs isvariable. Some atolls are very large—Kwajelein in the Marshall Islands of the SouthPacificis 120 kilometers long and as much as 24 kilometers across-but most are very much smaller, and rise only a few meters above the water. The 2,000-kilometercomplexof reefs known as the GreatBarrierReef, which forms agiganticnatural breakwater off the northeastcoastof Australia, is by far the greatestcoralstructure on Earth.

Coralreefs have fascinated scientists for almost 200 years, and some of the mostpertinentobservations of them were made in the 1830s by Charles Darwin on thevoyageof the Beagle. He recognized that there were three major kinds: fringing reefs,barrierreefs, and atolls; and he saw that they were related to each other in alogicaland gradationalsequence. A fringingreefis one that lies close to theshoreof somecontinentor island. Its surface forms anunevenand ratherroughplatform around thecoast, about thelevelof low water, and its outeredgeslopes downwards into the sea. Between the fringingreefand the land there is sometimes a smallchannelorlagoon. When thelagoonis wide and deep and thereeflies at some distance from theshoreand rises from deep water it is called abarrierreef. Anatollis areefin the form of a ring or horseshoe with alagoonin the center.

Darwin stheorywas that thesuccessionfrom onecoralreeftype to another could be achieved by the upward growth ofcoralfrom a sinking platform, and that there would be a progression from a fringingreef, through thebarrierreefstageuntil, with the disappearance through subsidence (sinking) of the central island, only a reef-enclosedlagoonoratollwouldsurvive. A long time after Darwin putforwardthistheory, some deep boreholes were drilled in thePacificatolls in the 1950s. Thedrillholes passed through more than a thousand meters ofcoralbefore reaching the rock substratum of the ocean floor, and indicated that thecoralhad been growing upward for tens of millions of years as Earth'scrustsubsided at arateof between 15 and 51 meters per million years. Darwin stheorywasthereforeproved basically correct. There are somesubmarineislands called guyots and seamounts, in which subsidence associated with sea-floor spreading has been too speedy forcoralgrowth to keep up.

Like mangrove swamps,coralreefs are extremely important habitats. Theirdiversityofcoralgenera is greatest in the warm waters of the Indian Ocean and the westernPacific. Indeed, they have been called themarineversionof thetropicalrain forest, rivaling theirterrestrialcounterparts in both richness ofspeciesand biologicalproductivity. They also havesignificancebecause they provide coastal protection, opportunities forrecreation, and arepotentialsources of substances like medicinal drugs. At present they are coming under avarietyof threats, of which two of the most important are dredging and the effects of increased siltation brought about byacceleratederosionfrom neighboring land areas.

Questions:
question_stem: According to paragraph 1, all of the following are needed for the growth of coral reefs EXCEPT
choices: tag: A
text: a solid base to grow on

tag: B
text: exposure to light

tag: C
text: the presence of river-borne sediment

tag: D
text: ocean temperatures of 21 °C or higher
answer_key: C
explanation: 【题目翻译】根据第1段，珊瑚礁的生长需要下列各项，但除了哪个选项？
A：坚实的基础

B：曝光

C：河道沉积物的存在

D：海洋温度21°C 或更高

【判定题型】：根据题干中出现的大写“EXCEPT”/"NOT" 等其他明显表示否定的词，可以判定本题为否定事实信息题，需要找出与原文信息不符的那个答案。

【关键词定位】根据题干关键词“the growth of coral reefs”,可以将出题范围锁定在 Passage 1。

【选项分析】
A：坚实的基础。原文 where there is a firm substratum，说明基础一定要坚实，对应选项 A 中：a solid base。

B：曝光。原文 the seawater is not rendered too dark，说明不能太暗，对应选项 B 中：light。

C：河道沉积物的存在。过多的沉淀物会遮住光不利于珊瑚礁生长，选项 C 错在 sediment。

D：海洋温度21°C 或更高。原文 Coral reefs are found where the ocean water temperature is not less than 21 °C，说明温度不能低于21°C，对应选项 D 中：21 °C or higher。

question_stem: the word “prerequisite” in the passage is closest in meaning to
choices: tag: A
text: precaution

tag: B
text: preparation

tag: C
text: requirement

tag: D
text: achievement
answer_key: C
explanation: 【题目翻译】文章中的“prerequisite”一词最接近于
A：预防措施

B：准备

C：要求

D：成就

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“prerequisite”,定位到原句“They will not grow in very deep water, so a platform within 30 to 40 meters of the surface is a necessary prerequisite for their development. ”。

【词汇解析】：词汇“prerequisite”的意思是“先决条件”,带入到原句中，原句的意思是“它们不会生长在非常深的水中，所以在离地表30至40米范围内的平台是它们发展的必要前提。”。

【选项分析】
A：预防措施。不符，错误
B：准备。不符，错误
C：要求。同义替换，正确
D：成就。不符，错误

question_stem: According to paragraph 1, algae are important because
choices: tag: A
text: they help build coral reefs

tag: B
text: they are the dominant type of sea life living on the reefs

tag: C
text: they compete with coral for zooplankton

tag: D
text: they are an important source of food available to corals
answer_key: A
explanation: 【题目翻译】根据第1段，藻类很重要，因为以下哪个选项？
A 它们帮助建造珊瑚礁。

B 它们是生活在礁石上的主要海洋生物。

C 它们和珊瑚争夺浮游动物。

D 它们是珊瑚的重要食物来源

【判定题型】：题目问的是文章中的具体细节信息，故根据题目问法可以判断本题为事实信息题。

【关键词定位】：根据关键词“algae”,定位到 Passage 1 第5句，原句为“However, in addition to corals there are enormous quantities of algae, some calcareous, which help to build the reefs.  ”，意思是“然而，除了珊瑚，还有大量的海藻，一些钙质，这有助于建造珊瑚礁。”
【逻辑分析】说明海藻帮助建造珊瑚礁。

【选项分析】
A 文章对应选项 A 中：they help build coral reefs。正确
B 它们是生活在礁石上的主要海洋生物。不是主要理由，错误。
C 它们和珊瑚争夺浮游动物。文章未提到这点，错误。
D 它们是珊瑚的重要食物来源。文章未提到珊瑚吃海藻。错误

question_stem: The word “complex” in the passage is closest in meaning to?
choices: tag: A
text: extension

tag: B
text: system

tag: C
text: region

tag: D
text: variety
answer_key: B
explanation: 【题目翻译】文章中“complex”这个词的意思最接近？
A：伸展
B：系统
C：地区
D：多样

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“complex”,定位到原句“The 2,000-kilometer complex of reefs known as the Great Barrier Reef, which forms a gigantic natural breakwater off the northeast coast of Australia, is by far the greatest coral structure on Earth.”。

【词汇解析】：词汇“complex”的意思是“复杂”,带入到原句中，原句的意思是“大堡礁（Great Barrier Reef）由2000公里长的珊瑚礁组成，在澳大利亚东北海岸外形成了巨大的天然防波堤，是迄今为止地球上最大的珊瑚结构。”。

【选项分析】
A：伸展。不符，错误
B：系统。同义替换，正确
C：地区。不符，错误
D：多样。不符，错误

question_stem: According to paragraph 2, how did Charles Darwin contribute to the understanding of coral reefs?
choices: tag: A
text: He identified the main types of coral reef and explained how they were related.

tag: B
text: He discovered the existence of coral reefs on a scientific voyage.

tag: C
text: He proved that reefs are mostly located very close to the shore.

tag: D
text: He saw the importance of reefs for the support of other marine life.
answer_key: A
explanation: 【题目翻译】根据第2段，查尔斯·达尔文如何有助于理解珊瑚礁？

A：他确定了珊瑚礁的主要类型，并解释了它们是如何联系在一起的。

B：他在一次科学航行中发现了珊瑚礁的存在。

C：他证明珊瑚礁大多位于离海岸很近的地方。

D：他看到珊瑚礁对于支持其他海洋生物的重要性。

【判定题型】：题目问的是文章中的具体细节信息，故根据题目问法可以判断本题为事实信息题。

【关键词定位】：根据关键词“Charles Darwin”,定位到 Passage 2第1句，原句为“Coral reefs have fascinated scientists for almost 200 years, and some of the most pertinent observations of them were made in the 1830s by Charles Darwin on the voyage of the Beagle. ”，意思是“近200年来，珊瑚礁一直吸引着科学家，其中一些最相关的观测是在19世纪30年代由查尔斯·达尔文在比格尔号航行时进行的。”。

【逻辑分析】说明达尔文识别三种珊瑚礁并且解释了他们的相关性。

【选项分析】
A：他确定了珊瑚礁的主要类型，并解释了它们是如何联系在一起的。与文章相符，正确。

B：他在一次科学航行中发现了珊瑚礁的存在。不是发现珊瑚礁的存在，而是对珊瑚礁进行了观察。错误。

C：他证明珊瑚礁大多位于离海岸很近的地方。他发现岸礁生长于靠近大陆或岛屿的岸边，这只是其中一个发现。错误。

D：他看到珊瑚礁对于支持其他海洋生物的重要性。第二段没有提出。错误。

question_stem: The word “pertinent” in the passage is closest in meaning to
choices: tag: A
text: extraordinary

tag: B
text: relevant

tag: C
text: intelligent

tag: D
text: famous
answer_key: B
explanation: 【题目翻译】文章中“pertinent”一词的意思最接近于
A：非常
B：相关
C：智能化
D：著名的

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“pertinent”,定位到原句“Coral reefs have fascinated scientists for almost 200 years, and some of the most pertinent observations of them were made in the 1830s by Charles Darwin on the voyage of the Beagle. ”。

【词汇解析】：词汇“pertinent”的意思是“相关的”,带入到原句中，原句的意思是“近200年来，珊瑚礁一直吸引着科学家，其中一些最相关的观测是在19世纪30年代由查尔斯·达尔文在比格尔号航行时进行的。”。

【选项分析】
A：非常。不符，错误
B：相关。意思相同，正确
C：智能化。不符，错误
D：著名的。不符，错误

question_stem: According to paragraph 2, which of the following is NOT characteristics of a barrier reef?
choices: tag: A
text: It is located away from the shore of the neighboring land.

tag: B
text: It is separated from neighboring land by a wide channel.

tag: C
text: It is located in deep ocean water.

tag: D
text: It surrounds a small, central lagoon.
answer_key: D
explanation: 【题目翻译】根据第2段，下列哪一项不是屏障礁的特征？
A：它坐落在离附近海岸不远的地方。
B：它与邻近的土地隔着一条宽阔的通道。
C：它位于深海中。
D：它环绕着一个小的中心泻湖。

【判定题型】：根据题干中出现的大写“EXCEPT”/"NOT" 等其他明显表示否定的词，可以判定本题为否定事实信息题，需要找出与原文信息不符的那个答案。

【关键词定位】：根据题干关键词“characteristics of a barrier reef”,可以将出题范围锁定在 Passage 2 。

【选项分析】
A：它坐落在离附近海岸不远的地方。符合，正确
B：它与邻近的土地隔着一条宽阔的通道。符合，正确
C：它位于深海中。符合，正确
D：它环绕着一个小的中心泻湖。原文 An atoll is a reef … with a lagoon in the center，说明中间有泻湖的是环礁，所以选项 D 不是堡礁的特点。

question_stem: 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.
choices: tag: A
text: Darwin claimed that, of the three types of coral reefs, only an atoll would be able to survive on a sinking platform.

tag: B
text: Darwin recognized that coral reefs achieved success by growing upward from a sinking land platform and becoming an atoll.

tag: C
text: Darwin argued that as a coral reef grew up from a sinking island, it would become a fringing reef, then a barrier reef, and finally, with the disappearance of the island, an atoll.

tag: D
text: Darwin’s theory helped explain the disappearance of a number of islands by showing how coral reef growth caused them to sink below the ocean surface.
answer_key: C
explanation: 【题目翻译】下面哪个句子最能表达文章中突出句子的基本信息？不正确的选择会以重要方式改变含义，或者漏掉必要的信息。
A：达尔文声称，在这三种珊瑚礁中，只有环礁能够在下沉的平台上生存。

B：达尔文认识到，珊瑚礁是通过从下沉的陆地平台向上生长而成为环礁而获得成功的。

C：达尔文认为，当一个珊瑚礁从一个下沉的岛屿上成长起来的时候，它会变成一个边缘的珊瑚礁，然后变成一个屏障的珊瑚礁，最后随着这个岛的消失，变成一个环礁。

D：达尔文的理论通过展示珊瑚礁的生长是如何导致许多岛屿沉入海底的，从而帮助解释了许多岛屿的消失。

【判定题型】：根据题目问法，题目要求选择和高亮句意思逻辑都最为接近的句子，故判断本题为句子简化题。

【句子分析】划线句子意为珊瑚礁从下沉的岛屿上长出来，然后变成裙礁，再变成堡礁，最后岛屿消失变成环礁。

【选项分析】
A：划线句是一种过程，而 A 选项不是。错误。
B：原文是下沉的岛屿，而选项中是下沉的陆地。错误。
C：选项 C 中：Darwin … as a coral reef … a sinking island, … fringing reef, … barrier reef, and … disappearance of the island, an atoll. 与文章意思相对应，正确。
D：文章是要说环礁的形成，而不是岛屿的消失。

question_stem: Which of the following can be inferred from paragraph 3 about the Pacific atolls?
choices: tag: A
text: They were once fringing reefs around the coasts of islands.

tag: B
text: They were first observed by Darwin during his voyage on the Beagle.

tag: C
text: They will eventually become fringing reefs.

tag: D
text: They are located where the ocean floor does not sink.
answer_key: A
explanation: 【题目翻译】从关于太平洋环礁的第3段中可以推断出以下哪一个？
A 它们曾经在岛屿的海岸边围着礁石。

B 它们是达尔文在比格尔号航行期间首次发现的。

C 它们最终会变成边缘的珊瑚礁。

D 它们位于海底不会下沉的地方。

【判定题型】：根据题干中出现的关键词“imply”/“infer”/“suggest”等其他表示推断的词，判定本题为推理题。

【关键词定位】：根据关键词“the Pacific atolls”,定位到 Passage 3第2、3句，原句为“A long time after Darwin put forward this theory, some deep boreholes were drilled in the Pacific atolls in the 1950s.  … and indicated that the coral … growing upward … as Earth's crust subsided .... Darwin s theory was therefore proved basically correct”。

【逻辑分析】说明太平洋环礁随着地球地壳减少慢慢上涨而形成的，证明达尔文理论正确，所以太平洋环礁最初就是围绕岛屿的裙礁

【选项分析】
A：选项 A 中” around the coasts of islands”与原文相对应，正确。
B:第三段没有提到比格尔航行，错误。
C:未提到边缘珊瑚礁。错误。
D:未提到有位于海底不会下沉的地方，错误

question_stem: Why does the passage provide the information that the drill holes in the Pacific atolls passed through more than a thousand meters of coral before reaching the rock substratum of the ocean floor?
choices: tag: A
text: To emphasize that according to Darwin’s view coral can grow at great depths

tag: B
text: To indicate how scientists knew the rate at which Earth’s crust had subsided

tag: C
text: To support the claim that coral reefs take millions of years to form

tag: D
text: To present the evidence that confirmed Darwin’s account of coral reef evolution
answer_key: D
explanation: 【题目翻译】为什么文章要提到：太平洋环礁上的钻孔在到达海底岩石底层之前穿过一千多米的珊瑚？
A：强调根据达尔文的观点，珊瑚可以在很深的地方生长。

B：表明科学家们如何知道地壳沉降的速度。

C：为了支持珊瑚礁的形成需要数百万年的说法。

D：提出证实达尔文关于珊瑚礁进化的说法的证据。

【判定题型】：根据题干问法“why …… provide”，题目询问“xxxxxx”(文章引用内容)的修辞目的，可以判断本题为修辞目的题。

【关键词定位】：根据关键词“The drill holes”,定位到 Passage 3最后两句话，原句为“The drill holes passed through more than a thousand meters of coral before reaching the rock substratum of the ocean floor, and indicated that the coral had been growing upward for tens of millions of years as Earth's crust subsided at a rate of between 15 and 51 meters per million years. @@@@Darwin s theory was therefore proved basically correct. @@@@There are some submarine islands called guyots and seamounts, in which subsidence associated with sea-floor spreading has been too speedy for coral growth to keep up.
”。
【引用内容分析】原文 Darwin s theory was therefore proved basically correct，说明举例太平洋环礁就是为了证明达尔文理论正确。

【选项分析】
A：强调根据达尔文的观点，珊瑚可以在很深的地方生长。未提及，错误。

B：表明科学家们如何知道地壳沉降的速度。未提及，错误。

C：为了支持珊瑚礁的形成需要数百万年的说法。未提及，错误。

D：提出证实达尔文关于珊瑚礁进化的说法的证据。与原文相符，正确

question_stem: According to paragraph 4, why have coral reefs been compared to tropical rain forests?
choices: tag: A
text: Both are located near the Indian and western Pacific Oceans.

tag: B
text: Both are home to a wide variety of species

tag: C
text: Both play an important role in protecting coastal islands.

tag: D
text: Both are threatened by the erosion of nearby land.
answer_key: B
explanation: 【题目翻译】根据第4段，为什么将珊瑚礁与热带雨林进行比较？
A：它们都位于印度洋和西太平洋附近。

B：两地都有各种各样的物种。

C：两者在保护沿海岛屿方面发挥着重要作用。

D：他们俩都受到附近土地侵蚀的威胁。

【判定题型】：根据题干问法“why …… ”，题目询问“xxxxxx”(文章引用内容)的修辞目的，可以判断本题为修辞目的题。

【关键词定位】定位到 Passage 4，原句为“Indeed, they have been called the marine version of the tropical rain forest, rivaling their terrestrial counterparts in both richness of species and biological productivity。”。

【引用内容分析】说明二者可以相比是因为物种都很丰富。

【选项分析】
A：Both are located near the Indian and western Pacific Oceans.A 选项只是说了地理位置，并没有说出表明了物种很丰富。错误
B：Both are home to a wide variety of species。提到物种丰富，与原文相符，正确。
C：Both play an important role in protecting coastal islands.这是物种多了之后的一个影响，错误。
D：Both are threatened by the erosion of nearby land.只是说了珊瑚受到的威胁之一，与比较目的无关。错误

question_stem: The word “potential” in the passage is closest in meaning to
choices: tag: A
text: powerful

tag: B
text: possible

tag: C
text: valuable

tag: D
text: reliable
answer_key: B
explanation: 【题目翻译】文章中的“potential”一词最接近于下列哪个选项？
A 有力量的
B 可能的
C 有价值的
D 可靠的

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“potential”,定位到原句“They also have significance because they provide coastal protection, opportunities for recreation, and are potential sources of substances like medicinal drugs.”。

【词汇解析】：词汇“potential”的意思是“潜在的”,带入到原句中，原句的意思是“它们也具有重大意义，因为它们提供海岸保护、娱乐机会，并且是药物等物质的潜在来源。”。

【选项分析】
A 有力量的。不符，错误
B 可能的。同义替换，正确
C 有价值的。不符，错误
D 可靠的。不符，错误