懒笔记
1998年考研英语真题 Section II Part A (5)
Postgraduate · 来自 1998年考研英语真题 · Section II Part A (5) · 阅读理解（四选一）

1998年考研英语真题 Section II Part A (5)

说明文 · 阅读理解（四选一） · 真题文章逐层精读

本页是 1998年考研英语真题 Section II Part A (5) 文章的精读视角页——这篇说明文全文 380 词、3 段，CEFR 难度 C1（C1 级在考研英语文章中占 91%），作者立场为「客观中立」；英文原文之外，本篇已有的 11 项精读维度逐项展开，其中能迁移到其他考研英语真题文章的判断方法（篇章结构、修辞、言外之意、作者态度、体裁速判）随各维度一并讲透。

精读最佳实践

本页解析里的段号（P1）都可以点——点一下，原文在顶部翻开并定位到该段，解析引用的原文同步标亮；合上原文，你还停在刚才读到的位置。点 P1 试试。

PASSAGE · 文章原文

3 段英文原文

以下为1998年考研英语真题 Section II Part A (5) 的阅读理解（四选一）原文，共 3 段。左侧 P1–P3 是段落编号——本页全部解析（结构、逐段、修辞、自检题）都以它为坐标回指原文，点击解析里的段号，原文即在顶部翻开并定位到该段、引用的原文同步标亮；合上原文仍停在当前阅读位置。原文保持卷面形态，不带翻译与标注。

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 now 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 comes to rest over a hot spot, the material rising from deeper layers creates a broad dome. As the dome grows, it develops deep 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).

PARAGRAPHS · 逐段精读

3 段逐段主旨与解读

逐段拆解1998年考研英语真题 的这篇原文——每段给出英文段落主旨、段落标题与中文解读，并提炼一条「这段为什么这样读」的具体方法。

  1. P1

    Hot Spots as Markers of Plate Movement

    Hot spots are relatively fixed volcanic markers that reveal the movement of tectonic plates.

    这一段承担全文的基础铺垫功能：它先说明 hot spots 为什么能够成为可靠的 reference points。没有“相对固定”和“留下火山轨迹”这两个前提，后文关于测量 plate motion 的论证便失去依据。

    抓末句功能
  2. P2

    Using Hot Spots to Measure Plate Motion

    Hot spots provide a reference frame for determining the absolute motion of tectonic plates.

    本段把第一段的“热点可作标记”进一步发展为可操作的 scientific measurement tool。它直接服务于全文主旨中的 reference points，并通过 African plate 的结论展示热点在研究 continental drift 中的实际价值。

    辨问题解法例证
  3. P3

    Hot Spots and Continental Breakup

    Hot spots can reshape continents by causing rifting and initiating new ocean formation.

    这一段完成全文的深化与收束：前两段说明 hot spots 如何帮助 scientists measure plate movement，本段则说明它们还能改变大陆本身。因而它对应文章主旨中的 crucial role，即热点既是观测板块漂移的标尺，也是可能触发 new ocean formation 的地球动力因素。

    串联裂海因果链
SELF CHECK · 段落自检题

3 道逐段细节自检题

针对1998年考研英语真题这篇原文，每段配 1 道细节题（ 1 个正确项 + 5 个干扰项 ，由懒笔记精读引擎基于本段命制，非试卷原题）。 选项默认中性；点「显示答案与解析」展开正确项、解析与最快解法，现代浏览器会同步高亮正确选项。

  1. 第 1 段 定位词 hot spots volcanic trails

    What function do hot spots and their volcanic trails serve?

    • A They prevent volcanoes from forming inside tectonic plates.
    • B They create the boundaries between drifting plates.
    • C They mark the passage of tectonic plates.
    • D They reveal that all hot spots move at the same speed.
    • E They supply new material for the ocean floor.
    • F They determine whether continents were once joined.
    显示答案与解析 收起答案与解析

    正确答案：C

    原文把 hot spots and their volcanic trails 比作 milestones，并明确说它们 mark the passage of the plates。正确项保留 mark 与 passage 的核心逻辑，只把 plates 表述为 tectonic plates，属于术语同义复现。障碍在于命题人没有重复完整原句，而是要求考生把 milestones 理解为“记录位置变化的路标”，进而还原其对 plate movement 的指示功能。

    尾句功能链 时间极紧时，不必顺读。直接用题干中最稀有的 volcanic trails 扫描，锁定 第1段；随后只读其所在句及前后一句，画出“痕迹—路标—板块经过”的压缩链。再用排除法检查六项：凡是把位置描述说成功能、把范围词 most 说成 all、或凭空加入因果的，都立即剔除；剩下与该压缩链同构的正确项。

  2. 第 2 段 定位词 determining plate motion hot spots

    Why are hot spots important in determining plate motion?

    • A They prove that all continental plates are moving apart.
    • B They show where Africa and South America were originally joined.
    • C They inject new material into the sea floor between continents.
    • D They provide a fixed reference for measuring plates against the earth's interior.
    • E They make the relative motion of two plates unnecessary to study.
    • F They cause the African plate to remain stationary.
    显示答案与解析 收起答案与解析

    正确答案：D

    原文先说明一块板相对另一块板的 motion，不能轻易转换为相对 earth's interior 的 motion；随后指出 hot spots anchored in deeper layers 提供解决问题所需的 measuring instruments。正确项将 anchored 和 measuring instruments 概念化为 fixed reference，准确补全了“相对谁测量”的关键。障碍在于选项没有机械复现原句，而是把物理锚定关系转写成测量学语言。

    测量缺口补位 最快做法是盯住题干里的 determining，而非宽泛的 hot spots。扫描到 determine、cannot readily be translated、measuring instruments 和 resolve the question 这一组“测量受阻—工具补位”词群，即锁定 第2段。无需逐句翻译，只在选项中寻找能够同时回应“测量”与“earth's interior 参照”的正确项；任何只谈大陆分离、海岸线或海底物质的选项，都是同段背景噪声。

  3. 第 3 段 定位词 continental plate remains over a hot spot

    What may happen when a continental plate remains over a hot spot?

    • A The plate becomes a permanent reference frame for all other plates.
    • B New sea-floor material forces the plate to drift away immediately.
    • C The rising material removes all deep fissures from the continent.
    • D The hot spot stops producing material from deeper layers.
    • E The continent may split along fissures, enabling the hot spot to initiate the formation of a new ocean.
    • F The continent necessarily breaks into several equal parts.
    显示答案与解析 收起答案与解析

    正确答案：E

    原文说明 dome 生长会形成 deep fissures，并指出在至少少数情况下 the continent may break entirely along some of these fissures，so that the hot spot initiates the formation of a new ocean。正确项用 split 改写 break entirely，并以 enabling 保留原文的主体归属：发生断裂的是 continent，而 initiate the formation of a new ocean 的主体是 hot spot。障碍在于该项跨越 broad dome 等中间环节，对因果链进行了压缩，同时仍保留 may 所表达的非必然性。

    因果链末端回收 高压时间下，用题干里最具动作性的 remains over a hot spot 定位其同义表达 comes to rest over a hot spot，直接锁定 第3段。随后不翻译整段，只沿逗号和连接词抓取末端名词：fissures、break、new ocean。选项筛选时优先做“模态核验”：题干是 may，原文有 may 和 few cases，因此只有既顺承因果链、又保留可能性的正确项可留；含 necessarily、all、immediately 的项可先秒排。

STRUCTURE · 篇章结构

3 个意群的说明文骨架

按说明文 的行文骨架切分意群，每个意群标注它覆盖的段落与对主旨的作用——逐段读完后回到这里俯瞰全篇，能看清作者为什么按这个顺序行文。

  1. P1

    热点的定义与基本特征

    这个 opening segment 介绍了 hot spots 这个 geological phenomenon 的基本 definition，强调它们是 isolated volcanic activity 的 regions，不同于 typical volcanoes 位于 plate boundaries，而是 located deep in plate interiors，并且 move slowly，会留下 trails of dead volcanoes 作为 plates movement 的 markers

    作为 expository text 的 introduction part，这个 sense group 建立了 foundational knowledge，让 readers 理解什么是 hot spots 以及它们的 distinctive characteristics，为后文探讨 their role as reference points 和 influence on plate movement 做好 conceptual preparation

    引入研究对象
  2. P2

    热点作为测量板块运动的参照系

    这个 sense group 从 plates are moving 这个 established fact 出发，通过 Africa and South America 的 example 说明 plate movement 的 evidence，然后引出 core argument：由于无法确定 absolute motion with respect to Earth's interior，需要 hot spots 作为 anchored measuring instruments 来 resolve this problem，最终得出 African plate is stationary 的 conclusion

    这是 expository text 的 main body 的第一个 supporting section，它 elaborates on 主旨中的 serve as reference points for measuring tectonic plate movement 这部分。通过 problem-solution structure，先提出 measurement challenge，再展示 hot spots 如何 provide the solution，让 abstract concept 变得 concrete and comprehensible

    阐明参照功能
  3. P3

    热点对板块运动的地球物理影响

    这个 concluding sense group 扩展了 hot spots 的 significance beyond reference function，说明它们 have important influence on geophysical processes that propel plates。通过 describing the mechanism：当 continental plate 停在 hot spot 上方，rising material 会 create a dome，develop fissures，potentially break the continent，从而 initiate new ocean formation。最后用 theoretical parallel 总结：就像 earlier theories explained continental mobility，hot spots 可以 explain their mutability

    这是 expository text 的 final body section，对应主旨中的 play a crucial role in continental drift。它通过 cause-effect explanation 展示 hot spots 不仅是 passive markers，更是 active agents in geological processes。这个 sense group 提升了 topic significance，从 measurement tool 到 driving force，符合说明文 progressive deepening 的 structural pattern

    揭示动力作用
MAIN IDEA · 速判主旨

5 步定位这篇文章的主旨

不读完全篇也能锁定主旨——以下 5 步按1998年考研英语真题 这篇原文的实际行文顺序给出，每步说明看哪里、看出什么，可直接迁移到其他考研英语文章。

  1. 首段核心现象识别 P1

    说明文的 opening paragraph 通常会 introduce 核心研究对象。这段开头就明确提出了 hot spots 这个 volcanic phenomenon，并给出了它的 defining characteristic：不在 plate boundaries 而在 plate interior，这种 contrast 暗示了 hot spots 的 special role

  2. 功能性陈述定位 P1

    首段最后一句 'milestones that mark the passage of the plates' 直接点明了 hot spots 的 measuring function。说明文常在首段结尾用 metaphor 或 functional description 来 summarize subject's key role，这是快速把握 main point 的关键信号

  3. 段首标记追踪 P2 P3

    第二段开头 'That the plates are moving is now beyond dispute' 承接首段的 measuring function，整段在 elaborate 这个 reference frame role。第三段开头 'The significance of hot spots is not confined to' 则用 not confined to 这个 expansion signal 引入了 additional role，即对 geophysical processes 的 influence。这种 progression 反映了主旨的 complete scope

  4. 因果链条识别 P3

    第三段中 'creates a broad dome' → 'develops deep fissures' → 'continent may break' → 'initiates the formation of a new ocean' 构成了完整的 causal chain。这个 mechanism explanation 揭示了 hot spots 不仅是 passive reference points，更是 active agents in continental change，这是主旨中 'crucial role' 的核心依据

  5. 双重功能整合 P1 P2 P3

    通过前面步骤，我们识别出 hot spots 有两个 core functions：作为 stationary reference points for measuring movement (段2)，以及作为 initiators of continental change through dome formation (段3)。主旨必须 integrate 这两个 dimensions，体现 subject 的 complete significance

主旨信号词 stationary P2 measuring instruments P2 initiates P3 significance P3 crucial role P3

MAIN IDEA · 主旨

这篇文章在说什么

热点是静止的火山区域,可作为测量板块运动的参考点,并通过形成穹顶和裂缝在大陆漂移中发挥关键作用,能够引发新海洋的形成。
Hot spots are stationary volcanic regions that serve as reference points for measuring tectonic plate movement and play a crucial role in continental drift by creating domes and fissures that can initiate new ocean formation.
WORD INFERENCE · 生词推断

5 个生词的上下文推断

不查词典，只用文中线索推出词义——每个词给出推断出的释义与 完整推理链。已收录进考研英语高频真题词集的单词可点击进入词条页。

  • milestone 里程碑;标志性事物

    我们先从 word formation 入手,发现 milestone 由 mile(距离)和 stone(石头)组成,暗示这是一种标记距离的 marker。然后看 syntactic structure,定语从句明确告诉我们它的 function 是 'mark the passage'。最后从 context 来看,前文铺垫了 volcanic trails 留下的 path,而 milestones 正是用来总结这种 tracking mechanism 的词。三条线索共同指向同一个 meaning:用来标记进程或位置的标志物。

    构词+句法+语篇角色三维分析
  • drift 漂移;缓慢移动

    从 synonymous relations 看,drifting 和 moving 在文中反复呼应。从 antonymous contrast 看,它与 stationary 对立,明确了 motion 的含义。从 domain-specific context 看,这是 geology 领域描述 plate tectonics 的术语,特指那种 slow, continuous movement。三条线索汇聚,表明 drift 是一种特定类型的 movement:缓慢漂移。

    同义反义加学科语境定位
  • anchor 固定;锚定

    从 causal logic 看,正因为 hot spots 被 anchored in deeper layers,它们才能 provide measuring instruments。从 functional analysis 看,anchor 的作用是创造一个 stationary reference frame。从 metaphorical mapping 看,deeper layers 对应 stability,surface 对应 mobility,anchored 就是将 hot spots 固定在 stable layer。三个维度都指向 'fixed' 或 'secured' 的含义。

    隐喻映射加功能因果推理
  • propel 推动;驱动

    从 morphology 看,pro- prefix 指向 forward motion。从 causal structure 看,propel 连接 geophysical processes 和 plate movement,表达 causation。从 process description 看,这不是 passive drift,而是有 active force 的 dynamic process。三条线索共同揭示:propel 表示一种主动的、强力的推动作用。

    构词句法加过程链定位
  • fissure 裂缝;裂隙

    虽然原文提供了 parenthetical definition,但从 process analysis 也能独立推断:dome growth 产生的 structural weakness,deep enough to cause continental breakup,along which continents split。这个 geological feature 必然是裂缝或断裂。两条线索指向同一 meaning。

    过程链输入输出分析
RHETORIC · 修辞手法

7 处修辞手法与仿写

每处修辞给出它在本文的具体用法、同类信号词清单与一份可直接套用的 写作仿写建议——读完能认，也能写。

  • 举例子

    P2

    作者在论述 plates are moving 这个关键观点时，specifically 选择了 Africa and South America 作为典型案例。通过 concrete example 展示两大陆正在 moving away from each other，同时提到 complementary coastlines 和 geological features 作为 supporting evidence。这个 example 让抽象的 plate movement theory 变得 tangible and convincing，直接服务于文章主旨中 hot spots 作为 measuring reference points 的必要性——只有先确立 plates do move，才能引出需要 stationary hot spots 来 measure 这种 movement 的逻辑链条。

    信号词 for example for instance such as take...as an example to illustrate a case in point namely specifically

    仿写： 当你需要 explain 一个 abstract scientific concept 时，问自己：能否找到一个 widely known 或 easily visualizable 的 instance？比如解释 erosion 时，可以说 'The Grand Canyon, for example, was carved by...'。仿写模版：【General statement】+ for example/for instance + 【Specific case with concrete details】+ 【How this case illustrates the general point】。关键是确保 example 和 main argument 之间有 clear logical connection。

  • 列数字

    P2

    文章在论证 African plate is stationary 时，给出了 precise temporal data：'the past 30 million years'。这个 specific number 不是 casual mention，而是 critical evidence 支撑 hot spots 作为 reliable reference frame 的核心论点。数字让 'stationary' 这个 claim 从 vague assertion 变成 quantifiable fact，directly 呼应文章主旨中 hot spots serve as reference points for measuring plate movement 的功能——只有 long-term stationary 的 reference 才具备 measurement value。

    信号词 million billion percent approximately over more than less than up to as many as nearly

    仿写： 当 making a claim 关于 duration, distance, quantity 或 magnitude 时，问自己：这个 description 能否被 quantified？与其说 'a long time'，不如说 'over 50 years'。仿写模版：【Claim】+ 【specific numerical data】+ 【unit of measurement】+ 【what this number proves or illustrates】。注意数字要 serve the argument——不是 stack numbers randomly，而是选择 most relevant data point 来 strengthen your main point。

  • 下定义

    P1

    文章开篇就对 hot spots 进行 technical definition：'isolated volcanic activity known to geologists as hot spots'。这个 definition 是整篇文章的 conceptual foundation——它 clarifies what exactly 作者在 discussing，为后续关于 hot spots' unique characteristics（not at plate boundaries, move slowly, leave trails）的 elaboration 奠定 terminological basis。这直接服务文章主旨：只有先 define 清楚 what hot spots are，才能论述它们作为 stationary reference points 和 geophysical drivers 的 dual roles。

    信号词 known as defined as refers to is called means is are termed designated as understood as

    仿写： 当 introducing 一个 technical term 或 specialized concept 时，采用 'X is/refers to Y' structure。Y 部分包含两层：broader category（它属于什么 class）+ distinguishing features（它与同类的 difference）。仿写模版：【Term】+ is/refers to/is defined as + 【broader category】+ that/which + 【specific characteristics that differentiate it】。比如：'Photosynthesis is a biological process through which plants convert light energy into chemical energy'。确保 definition 在文中的 positioning——通常在 first mention of the term。

  • 作比较

    P1

    文章在 第1段 中将 hot spots 与 'most of the world's volcanoes' 进行 systematic comparison，强调 unlike typical volcanoes，hot spots 'are not always found at the boundaries of the great drifting plates'，反而 'many of them lie deep in the interior of a plate'。这个 comparison 通过 contrast 突出 hot spots 的 unique positioning characteristic，这正是它们能成为 stationary reference points 的 geographical prerequisite——因为 not tied to plate boundaries，它们才可能 independent of plate movement。这直接支撑文章主旨关于 hot spots as measuring instruments 的论述。

    信号词 unlike in contrast to whereas while on the contrary conversely however differ from compared to in comparison with

    仿写： 当 introducing 一个 novel concept 时，问：读者 already know 什么 similar thing 可以作为 reference point？使用 'Unlike X' 或 'In contrast to X' 开启 comparison。仿写模版：【Unlike/In contrast to + familiar item】+ 【subject】+ 【key difference】。或者：【Subject】+ differs from + 【comparison object】+ in that + 【specific aspect】。关键是选择 meaningful comparison basis——差异必须 relevant to your argument，而非 arbitrary differences。

  • 打比方

    P1

    文章在 第1段 结尾用 figurative language：'The hot spots and their volcanic trails are milestones that mark the passage of the plates'。这里将 hot spots 和 volcanic trails 比作 'milestones'（里程碑），这个 metaphor 非常 powerful——milestones 在 physical world 中是 fixed reference points 用于 measure distance traveled，完美 mirrors hot spots 在 geological context 中作为 stationary markers tracking plate movement 的功能。这个 analogy 让 abstract geophysical concept 变得 immediately graspable，直接呼应文章主旨中 hot spots as reference points 的核心论点。

    信号词 like as resemble similar to is a kind of serves as acts as functions as can be seen as is analogous to

    仿写： 当 explaining 一个 complex mechanism 或 abstract relationship 时，寻找 familiar objects or processes 具有 similar structural features。问自己：这个 phenomenon 的 essential function 像什么 everyday thing？仿写模版：【Subject】+ is/are (like) + 【familiar object】+ that + 【shared functional characteristic】。比如：'DNA is like a blueprint that guides...'。确保 metaphor 的 mapping 是 clear——读者应能 immediately see the parallel。Avoid mixed metaphors 和确保 comparison 不会 mislead。

  • 作诠释

    P2

    在 第2段 中，作者先提出 'motion of one plate with respect to another cannot readily be translated into motion with respect to the earth's interior'，然后 elaborate 这个 difficulty：'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'。这是 classic interpretation——将 preceding technical statement 展开成 concrete scenarios，clarifying why 存在这个 measurement challenge。这个 interpretation 为 hot spots 作为 solution 铺垫：正因为 relative motion 存在 ambiguity，才需要 anchored reference points，直接 supports 文章主旨关于 hot spots' measuring function。

    信号词 that is in other words this means to put it another way namely specifically more precisely to clarify what this means is in essence

    仿写： 当 making 一个 complex or abstract claim 时，anticipate reader confusion：哪部分可能 unclear？使用 follow-up sentences 来 rephrase or expand。仿写模版：【Initial technical statement】+ This means that/In other words/That is to say + 【more accessible explanation or concrete illustration】。或者：【Claim】+ It is not possible to + 【what cannot be done】+ 【why this limitation matters】。Key 是 maintain logical connection——interpretation 应 deepen understanding，而非 repeat the same content。

  • 分类别

    P3

    文章在 第3段 论述 hot spots 的 significance 时，明确分为两个 categories：'their role as a frame of reference'（第一类功能）和 'important influence on the geophysical processes that propel the plates'（第二类功能）。通过这个 classification，作者 systematically organize hot spots 的 dual significance——既是 measuring tool，又是 dynamic driver。这个 categorization 直接对应文章主旨的两个 parallel clauses：serve as reference points（measurement role）和 play a crucial role in continental drift（geophysical role），展现了说明文的 logical rigor。

    信号词 classified into divided into falls into categories can be grouped as types of kinds of one is...another is first...second not only...but also both...and

    仿写： 当 discussing 一个 subject with multiple aspects 或 functions 时，explicitly divide 它们 into categories。仿写模版：【Subject's significance/role/types】+ is not confined to + 【Category A】+ It also + 【Category B】。或使用 enumeration：【Subject】+ can be classified into + 【number】+ types/categories: first/one is + 【Category A】+ second/another is + 【Category B】。确保 classification basis 是 clear and consistent——categories 应该 mutually exclusive and collectively exhaustive（MECE principle）。

IMPLIED MEANING · 言外之意

4 处话里有话

作者没有明说、但靠信号词传递出来的态度与暗示——每处给出原文片段、信号词类型与解读。

  • 热点与板块边界的反常关系

    P1
    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.

    对比类 Unlike In contrast However On the contrary Whereas While But

    这个 implication 是在告诉 readers：hot spots 并非 ordinary volcanic features，它们的 location pattern 违反了 conventional understanding。这种 unusual characteristic 为后文 establishing hot spots as reference points 奠定基础，因为只有 stationary 且 independent of plate boundaries 的 features 才能 serve as 可靠的 measuring instruments。对 main thesis 的 value 在于：通过 emphasize their uniqueness，justify 为什么 hot spots 能成为 study plate movement 的 key tool。

  • 板块运动的测量困境

    P2
    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.

    模糊限制语 cannot readily not easily difficult to hard to cannot simply not possible to challenging to

    这段的 underlying message 是：existing methods 有 fundamental flaw，we need 新的 approach。通过 emphasize the impossibility of determining absolute motion，作者在 create necessity for hot spots as fixed reference points。这个 implication 直接 supports the thesis 关于 hot spots serving as measuring instruments 的部分，因为 problem definition 使得 solution 显得 indispensable。对 overall argument 的 contribution 是通过 establish 一个 methodological gap 来 elevate hot spots 的 scientific significance。

  • 热点功能的超预期扩展

    P3
    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.

    范围限制突破类 not confined to not limited to beyond more than just not merely not only extend beyond

    这个 implicit meaning 在传达：hot spots 不只是 passive markers，它们是 active agents in geological processes。通过 signal 功能的 expansion，作者 elevate hot spots 从 measuring tools 到 driving forces。这对 thesis 的 contribution 体现在 demonstrate hot spots 的 dual significance，既 support plate movement research 又 participate in continental evolution。这种 layered importance makes the argument more compelling，因为 hot spots 不仅 help us understand 现有 processes，还 initiate fundamental geological changes。

  • 理论发展的对称性暗示

    P3
    Thus just as earlier theories have explained the mobility of the continents, so hot spots may explain their mutability (inconstancy).

    类比类 just as similarly likewise in the same way parallel to analogous to comparable to

    这个 implication 传达的是：hot spot theory 代表着与 earlier continental drift theories 同等 level 的 scientific breakthrough。通过 create this parallel，作者 implicitly argue hot spots 不仅是 supplementary detail，而是 complete the picture of continental dynamics。对 main thesis 而言，这个 implication 将 hot spots 的 role 提升到 foundational level，showing 它们不仅 measure movement 还 explain why continents change。这种 theoretical elevation 是 article 的 culmination，将所有 previous points 整合成一个 comprehensive understanding of geological processes。

AUTHOR ATTITUDE · 作者态度

作者态度：客观中立

结论先行：本文作者态度为客观中立（ Objective and informative with scholarly emphasis）。下面是按步骤还原的判断过程与文中的态度信号词。

  1. 首段动词和句式 P1

    说明文的 opening tone 往往就 establish 了整体 attitude。如果作者用 neutral descriptive verbs 比如 'are'、'lie'、'mark'，而不是 evaluative words 像 'surprisingly'、'unfortunately'，那就说明作者保持着 scientific objectivity。

  2. 过渡词功能 P1 P2

    Transitional words 在说明文里 reveal author's intention。如果用 'however'、'in contrast' 是为了 present different aspects objectively，而不是 'regrettably'、'fortunately' 这种带 value judgment 的 transitions，说明作者在 maintaining neutrality while organizing information。

  3. 证据类型识别 P2 P3

    说明文作者如果 cite specific data、examples、analysis results，说明他们在 build credibility through evidence 而非 personal conviction。这种 evidence-based writing 是 objective informative attitude 的 hallmark，因为作者让 facts speak for themselves。

  4. 结论语气把控 P3

    说明文的 conclusion 如果 emphasize scientific importance 用 measured language，而不是 call for action 或 express strong emotions，就说明作者 throughout 都在 maintain professional objectivity。这种 balanced closing reinforces 之前建立的 neutral scholarly tone。

文中的态度信号词

  • known to P1

    'Known to geologists' 这个 phrase 表明作者在 citing established scientific knowledge，而不是 proposing personal theories。这种 reference to scientific community establishes authority through consensus，是 objective informative writing 的典型 marker。

    同类词 recognized as referred to as identified as termed called

  • beyond dispute P2

    'Now beyond dispute' 强调 scientific consensus，但它在说明文语境里不是 aggressive assertion，而是 stating current state of knowledge。作者用这个 phrase 来 distinguish established facts from ongoing debates，maintaining objectivity by clarifying certainty levels。

    同类词 well-established widely accepted undeniable indisputable universally acknowledged

  • it appears that P2

    'It appears that' 是 hedging language，表明作者在 presenting conclusions cautiously。这种 tentative phrasing 体现 scientific humility，acknowledging 当前结论是 based on available evidence 但可能 subject to revision，这是 objective scholarly writing 的重要 characteristic。

    同类词 it seems that evidence suggests data indicate findings show results imply

  • significance P3

    'The significance of hot spots' 表明作者在 highlighting scientific importance，但用的是 neutral evaluative term。不是 'fascinating' 或 'disappointing'，而是 'significance'，这种 formal academic vocabulary maintains professional distance while acknowledging importance。

    同类词 importance value relevance implications contribution

  • may explain P3

    'Hot spots may explain their mutability' 中的 'may' 是 modal verb of possibility，showing 作者 presenting hypothesis rather than proven fact。这种 epistemic modality 体现 scientific caution，是 objective presentation 的 linguistic marker，因为作者 acknowledge uncertainty。

    同类词 might account for could indicate possibly suggest potentially reveal may contribute to

GENRE · 速判体裁

30 秒判定这是一篇说明文

体裁决定读法与出题套路。以下判断步骤与标志词全部以本文为例，可直接迁移到其他考研英语 真题文章。

如何快速判断这是一篇说明文？

  1. 首句功能识别 P1

    说明文的 opening 通常会客观地 present 一个 subject（本文是 hot spots），而议论文会直接 state a position 或 claim，新闻报道则会 lead 一个 recent event 或 breaking news。Hot spots 的 introduction 是 neutral description，没有 opinion 或 time-sensitive news。

  2. 段落组织模式 P1 P2 P3

    本文采用典型的 expository structure：第1段 做 definition 和 description，第2段 解释 function（作为 reference frame），第3段 分析 significance 和 influence。这是 explanation-oriented structure，不是 persuasion-oriented（议论文会 build arguments）或 timeliness-oriented（新闻会 prioritize latest info）。

  3. 时态和情态动词 P1 P2 P3

    文章通篇使用 present tense（'are scattered'、'move'、'appears'）描述 general scientific facts，没有 past tense news reporting（'happened'、'announced'），也没有 strong modal verbs 表达 opinion（'should be studied'、'must conclude'）。这是 timeless explanation 的 marker。

  4. 语言客观性程度 P1 P2 P3

    文章使用 objective scientific terminology（'geologists'、'volcanic activity'、'geophysical processes'），没有 subjective adjectives（'terrible'、'wonderful'）或 persuasive phrases（'we must'、'it is clear that'），也没有 journalistic attributions（'according to officials'、'sources say'）。纯粹的 factual presentation。

  5. 四维特征交叉验证 P1 P2 P3

    本文完全符合 expository writing 的 defining features：primary goal 是 to inform and explain（不是 to persuade 或 to report breaking news），structure 是 knowledge-building（不是 argument-building 或 event-sequencing），language 是 factual（不是 opinionated 或 source-attributed），tense 是 present for general truths（不是 past for events）。

哪些词暴露了说明文体裁？

  • are known to geologists as P1 说明对象定义解释词 are known as are called are referred to as are defined as is termed
  • Unlike P1 事物属性功能描述词 In contrast to Different from Distinguished by Characterized by Features include
  • Most of the hot spots P1 事物属性功能描述词 Most of Many of them Some A few The majority of
  • for example P2 说明顺序与例证词 for instance such as including namely specifically
  • provide P2 事物属性功能描述词 supply offer serve as function as act as
  • It appears that P2 说明顺序与例证词 It seems that Evidence suggests Studies show Research indicates Data reveal
  • The significance of P3 事物属性功能描述词 The importance of The role of The function of The purpose of The effect of
  • When...creates P3 事物属性功能描述词 As...develops causes results in leads to produces
  • Thus P3 说明顺序与例证词 Therefore Hence Consequently As a result Accordingly
SENTENCE INSIGHTS · 句子精讲

8 句真题句逐层精讲

下列真题句各有独立的句子解析页——中文翻译、结构树逐层拆解、成分与时态、考点讲解与真题高频词。点击句子进入完整解析。

FAQ · 常见问题

关于 1998年考研英语真题 Section II Part A (5) 的常见问题

1998年考研英语真题 Section II Part A (5) 文章的主旨是什么？
热点是静止的火山区域,可作为测量板块运动的参考点,并通过形成穹顶和裂缝在大陆漂移中发挥关键作用,能够引发新海洋的形成。（英文表述：Hot spots are stationary volcanic regions that serve as reference points for measuring tectonic plate movement and play a crucial role in continental drift by creating domes and fissures that can initiate new ocean formation.）
1998年考研英语真题 Section II Part A (5) 文章是什么体裁？难度如何？
体裁为说明文，作者立场是客观中立（Objective and informative with scholarly emphasis）。CEFR 难度 C1，全文 380 词、3 段；在考研英语全部 70 篇真题文章中，C1 级共 64 篇（占 91%）。
1998年考研英语真题 Section II Part A (5) 文章的篇章结构是怎样的？
全文 3 段按说明文骨架分为 3 个意群：第1段——热点的定义与基本特征；第2段——热点作为测量板块运动的参照系；第3段——热点对板块运动的地球物理影响。
1998年考研英语真题 Section II Part A (5) 文章的作者态度是什么？
作者态度是客观中立（Objective and informative with scholarly emphasis）。判断路径：首段动词和句式 → 过渡词功能 → 证据类型识别 → 结论语气把控；文中的态度信号词包括 known to（第1段）、beyond dispute（第2段）、it appears that（第2段）、significance（第3段）、may explain（第3段）。
1998年考研英语真题 Section II Part A (5) 文章中有哪些值得积累的生词？
按文中出现顺序共 5 个：milestone（里程碑;标志性事物）、drift（漂移;缓慢移动）、anchor（固定;锚定）、propel（推动;驱动）、fissure（裂缝;裂隙），每个词的词义都可以由文中上下文线索推断得出。

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