懒笔记
2017年12月英语四级真题第1套 Part III Section C (1)
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2017年12月英语四级真题第1套 Part III Section C (1)

说明文 · 阅读理解（四选一） · 真题文章逐层精读

本页是 2017年12月英语四级真题第1套 Part III Section C (1) 文章的精读视角页——这篇说明文全文 349 词、3 段，CEFR 难度 C1（C1 级在英语四级文章中占 32%），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，其中能迁移到其他英语四级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2017年12月英语四级真题第1套 Part III Section C (1) 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。

That people often experience trouble sleeping in a different bed in unfamiliar surroundings is a phenomenon known as the "first-night" effect. If a person stays in the same room the following night they tend to sleep more soundly. Yuka Sasaki and her colleagues at Brown University set out to investigate the origins of this effect.

Dr. Sasaki knew the first-night effect probably has something to do with how humans evolved. The puzzle was what benefit would be gained from it when performance might be affected the following day. She also knew from previous work conducted on birds and dolphins that these animals put half of their brains to sleep at a time so that they can rest while remaining alert enough to avoid predators(捕食者). This led her to wonder if people might be doing the same thing. To take a closer look, her team studied 35 healthy people as they slept in the unfamiliar environment of the university's Department of Psychological Sciences. The participants each slept in the department for two nights and were carefully monitored with techniques that looked at the activity of their brains. Dr. Sasaki found, as expected, the participants slept less well on their first night than they did on their second, taking more than twice as long to fall asleep and sleeping less overall. During deep sleep, the participants' brains behaved in a similar manner seen in birds and dolphins. On the first night only, the left hemispheres(半球) of their brains did not sleep nearly as deeply as their right hemispheres did.

Curious if the left hemispheres were indeed remaining awake to process information detected in the surrounding environment, Dr. Sasaki re-ran the experiment while presenting the sleeping participants with a mix of regularly timed beeps(蜂鸣声) of the same tone and irregular beeps of a different tone during the night. She worked out that, if the left hemisphere was staying alert to keep guard in a strange environment, then it would react to the irregular beeps by stirring people from sleep and would ignore the regularly timed ones. This is precisely what she found.

PARAGRAPHS · 逐段精读

3 段逐段主旨与解读

逐段拆解2017年12月英语四级真题第1套 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

    Introducing the First-Night Effect

    The paragraph introduces the first-night effect and Dr. Sasaki's investigation into its cause.

    对于全文主旨而言，本段先搭建了问题框架：人为何会在陌生地点第一晚睡不好，即 why the first-night effect occurs。它为后两段的 evolutionary explanation、brain evidence 和 beep experiment 预留了逻辑空间，使全文形成“现象—探因—验证”的清晰 structure。

    现象界定加研究引入
  2. P2

    Evidence of Uneven Brain Sleep

    Dr. Sasaki's study found that the left hemisphere remains less deeply asleep on the first night in an unfamiliar place, suggesting an evolutionary protective function.

    本段是全文的核心证据段，它把首段提出的 sleep problem 转化为可观察的 brain activity difference。鸟类和 dolphins 的机制构成类比参照，而人类 left hemisphere 的浅睡结果初步支持了文章主旨中的 evolutionary protective mechanism，不过“它是否真的在警戒环境”仍需下一段进一步验证。

    锁定左右半球睡眠差异
  3. P3

    Testing the Brain's Night Watch

    The beep experiment confirmed that the less deeply sleeping left hemisphere remains alert to unusual sounds in an unfamiliar environment.

    本段完成了全文最关键的因果闭环：前段发现左半球 sleep less deeply，本段证明它会对 unusual sounds 作出警戒反应。由此，首夜效应不再只是陌生环境中的睡眠障碍，而被解释为一种能侦测潜在 danger 的 adaptive mechanism，这直接落实了全文文章主旨。

    异常蜂鸣验证警戒反应
SELF CHECK · 段落自检题

3 道逐段细节自检题

针对2017年12月英语四级真题第1套这篇原文，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 Yuka Sasaki set out to investigate

    What did Yuka Sasaki and her colleagues set out to investigate?

    • A How people can sleep more soundly on the second night.
    • B Why birds and dolphins avoid predators while resting.
    • C The origins of the first-night effect.
    • D Whether unfamiliar rooms affect brain activity in healthy people.
    • E How long it takes people to fall asleep in a new bed.
    • F Whether irregular beeps can wake sleeping participants.
    显示答案与解析 收起答案与解析

    正确答案：C

    正确项准确对应 investigate 的宾语中心：origins of this effect。它没有把文章中的 phenomenon 扩大为所有 sleep problems，也没有偷换成实验已经证明的 mechanism。命题障碍在于 first-night effect 容易让考生只选“陌生环境中的睡眠困难”这一表层描述；但题干问的是研究者要追查的 origins，正确项必须保留“起源”这一抽象研究层级。

    截取动词宾语 时间极紧时，直接在题干中抓取 set out to investigate，而不是先读完全文；在 第1段 扫描同形动词结构及其紧邻宾语。随后采用“动词宾语截取法”：只比较各选项能否充当 investigate 的直接研究对象，能完整嵌入该结构的正确项即为答案项。这个方法跳过对每个选项逐一翻译，尤其适合 purpose 题。

  2. 第 2 段 定位词 participants' brains first night

    What did Dr. Sasaki observe about the participants' brains on their first night?

    • A Their right hemispheres slept less deeply than their left hemispheres.
    • B Both hemispheres remained equally alert throughout the night.
    • C Their brains slept more deeply than those of birds and dolphins.
    • D Their left hemispheres slept less deeply than their right hemispheres.
    • E Their left hemispheres reacted only to regularly timed beeps.
    • F Their brains showed no difference between the first and second nights.
    显示答案与解析 收起答案与解析

    正确答案：D

    正确项完整保留原文的比较关系：left hemispheres 对 right hemispheres，以及 did not sleep nearly as deeply 的程度信息；同时受 first night only 限制。它是实验观察的直接改写，不额外添加因果结论。设置的主要障碍是原文先报告 sleep less well、fall asleep 的整体表现，随后才转入 hemispheres；考生若只抓住“睡眠较差”，就会错过题干 brains 所要求的精确证据。

    半球方向箭头 在 第2段，先不读前面的 evolutionary explanation，直接凭题干的 brains + first night 跳读到含 hemispheres 的句子。然后用“二元箭头法”判定：把原文压缩为 left/right 与 less deeply/deeply 两条方向箭头，逐项检查方向是否完全一致；四个要素都不倒置的正确项即为答案项。这比逐项翻译整句更快。

  3. 第 3 段 定位词 irregular beeps

    What response to the irregular beeps supported Dr. Sasaki's idea?

    • A They helped the participants fall asleep more quickly.
    • B They were ignored by the left hemisphere.
    • C They made the right hemisphere sleep less deeply.
    • D They caused both hemispheres to become equally alert.
    • E They stirred the participants from sleep.
    • F They had no effect on the sleeping participants.
    显示答案与解析 收起答案与解析

    正确答案：E

    正确项对应预测中 react to the irregular beeps by stirring people from sleep，且随后 This is precisely what she found 确认该预测得到验证。它回答的是具体 response，而非重复研究者的警觉性推测。障碍在于题目使用 supported Dr. Sasaki's idea，考生可能误选“left hemisphere stayed alert”这类理论表述；但 evidence 题需要的是可观察的反应结果。

    蜂鸣配对表 时间紧张时，在 第3段 用 irregular beeps 作唯一检索词，立即寻找它所在句中的动作动词；不要先消化整段理论。接着画一个两列微表：irregular 对应何种 response，regularly timed 对应何种 response。正确项是与 irregular 同列、且能解释 supported 的答案项。此法直接利用实验对照的配对结构。

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

    引入研究现象与研究者

    这个意群 introduces 了一个 common phenomenon 叫做 first-night effect，即人们在 unfamiliar surroundings 的第一晚往往 sleep poorly，但 the following night 就会 sleep more soundly。接着 presents 了研究者 Yuka Sasaki 和她的 colleagues，他们决定 investigate 这个 effect 的 origins。

    作为 expository writing 的 opening，这个意群 establishes 了研究的 research question，为后续的 investigation 和 findings 搭建 context。它通过描述一个 relatable phenomenon 来 engage readers，同时 introduces 研究的 主角 Dr. Sasaki，这是 typical 的科学说明文 structure，从 observation 引入到 research initiative。

    提出待研究现象
  2. P2

    研究假设、方法与初步发现

    这个意群 explains Dr. Sasaki 的 reasoning process：她 hypothesized 这个 effect 跟 human evolution 有关，并且受到 birds 和 dolphins 的 half-brain sleep pattern 启发，wondered 人类是否也 doing the same thing。然后 describes 她的 experimental method，studying 35 healthy participants 在 unfamiliar environment 中的 sleep。最后 presents 她的 key finding：participants 的 left hemisphere 在 first night 并没有 sleep as deeply as right hemisphere，这和 birds/dolphins 的 behavior similar。

    这是 expository structure 中的 core investigation section。它 transitions from hypothesis formation 到 empirical testing，再到 preliminary findings。在 scientific exposition 中，这个 segment 承担 explaining the logic behind research design 和 presenting initial evidence 的 dual function。它通过 comparative biology (birds and dolphins) 来 build explanatory framework，这是说明文常用的 analogical reasoning strategy，帮助 readers understand 复杂的 biological mechanism。

    揭示大脑半球的不对称睡眠
  3. P3

    验证性实验与结论确认

    这个意群描述了 Dr. Sasaki 的 follow-up experiment。她 curious 左半球是否真的 remaining awake to process environmental information，于是 re-ran 实验，这次在 participants sleeping 时 presenting different types of beeps。她 worked out 一个 prediction：如果 left hemisphere 确实 staying alert，it would react to irregular beeps 而 ignore regular ones。最后 states：This is precisely what she found，完全 confirming 她的 hypothesis。

    这是 expository structure 的 confirmation section，它把 preliminary observation 从 correlation 提升到 causation。在 scientific exposition 中，这种 follow-up experiment 是 crucial，因为它 tests specific mechanism 而不仅是 documents pattern。这个意群通过 prediction-testing-confirmation 的 tight logical sequence 来 solidify 主旨的 explanatory power。结尾的 precisely 一词 provides definitive closure，这是 expository writing 中 signaling conclusive evidence 的 typical marker。

    证实警觉机制的功能性
MAIN IDEA · 速判主旨

4 步定位这篇文章的主旨

不读完全篇也能锁定主旨——以下 4 步按2017年12月英语四级真题第1套 这篇原文的实际行文顺序给出，每步说明看哪里、看出什么，可直接迁移到其他英语四级文章。

  1. 首段现象定义与研究者登场 P1

    说明文的 opening paragraph 通常会 introduce 要解释的 phenomenon，同时点明 researcher 或 research team，这为后文的 investigation 和 findings 搭建 framework

  2. 假设-实验-发现的逻辑链 P2

    说明文的 body paragraphs 会详细描述 research methodology 和 discoveries。本文通过 birds and dolphins 的 analogy 提出 hypothesis，然后用 experiment 验证，最终发现 left hemisphere 保持相对清醒的 pattern。这种从 hypothesis 到 verification 的 logic chain 就是文章的 explanatory core

  3. 功能验证实验确认机制 P3

    第三段通过 irregular beeps experiment 验证了 left hemisphere 的 monitoring function，用 precisely what she found 这样的 confirmation language 明确了 mechanism。这个 functional explanation（在陌生环境中保持警觉的 protective mechanism）正是文章主旨的 final piece

  4. 三层解释框架整合 P1 P2 P3

    说明文主旨必须整合三个 dimensions：what（first-night effect 是什么）、how（hemisphere asymmetry 如何运作）、why（evolutionary protection 为何存在）。只有将这三层 combined 才能形成 complete explanation，这正是本文主旨的 structure

主旨信号词 evolved P2 remaining alert P2 similar manner P2 precisely P3

MAIN IDEA · 主旨

这篇文章在说什么

佐佐木博士的研究揭示了"首夜效应"的产生原因:在陌生环境中,大脑的一侧半球会保持更高的警觉性,类似于鸟类和海豚,这是一种进化形成的保护机制,用于在新环境中睡眠时防范潜在威胁。
Research by Dr. Sasaki reveals that the first-night effect occurs because one brain hemisphere remains more alert in unfamiliar environments, similar to birds and dolphins, serving as an evolutionary protective mechanism against potential threats while sleeping in new surroundings.
WORD INFERENCE · 生词推断

4 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。已收录进英语四级高频真题词集的单词可点击进入词条页。

  • soundly 熟睡地、酣睡地

    我们先看 context：第一晚 trouble sleeping 是负面状态，第二晚用 more soundly 来形容，而且有 more 这个比较级，说明是一个改善的方向。再看 morphology：sound 作为形容词表示"健全的"，加上 -ly 变成副词修饰 sleep。两条线索都指向同一个结论：soundly 表示睡得很好、很沉。

    词根分析结合语境对比双重验证
  • predator 捕食者、食肉动物

    从 logical relationship 看，animals 需要保持 alert 去 avoid predators，说明 predators 是一种威胁。从 morphology 看，pred- 表示"捕获"，-or 表示执行者，合起来就是"捕获者"。两条 clues 共同指向：predators 是那些捕食其他动物的生物。

    功能角色定位结合词根词缀验证
  • hemisphere 半球

    从 context 看，brain 被描述为有 left 和 right 两个 hemispheres，它们可以独立地进入不同的 sleep states，说明这是 brain 的两个对称部分。从 word structure 看，hemi- 表示"半"，sphere 表示"球"，合在一起就是"半球"。两条线索完美吻合：hemisphere 就是大脑的半球。

    前缀拆解加核心词义的三步验证法
  • stir 唤醒、惊动、使离开某种状态

    从 prepositional phrase 看，stir people from sleep 表示使人离开 sleep 这个 state。从 semantic contrast 看，stir 与 ignore 形成对立，ignore 是不反应，stir 就是引起反应。综合这两条 clues，stir 在这里的意思就是"唤醒、惊动"，让人从睡眠中被打断或半醒。

    对比动词结合介词搭配定向推断
RHETORIC · 修辞手法

5 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 第2段 中通过 birds and dolphins 这两个具体的 animals 来说明 half-brain sleep 的现象。这个 concrete example 让读者能够直观理解 the first-night effect 可能的 evolutionary mechanism，为后续揭示 humans 也有类似的 brain hemisphere asymmetry 做铺垫，supports the main thesis 即这是一种 protective adaptation。

    信号词 for example for instance such as like including take...for example a case in point to illustrate

    仿写： 当你需要解释一个 abstract biological or psychological phenomenon 时，可以先思考：有没有其他 species 或 everyday situations 展现类似的 pattern？选择 readers 相对熟悉的 examples，用 'for instance' 或 'such as' 引入。模版：'This phenomenon is not unique to humans. [Other creatures/situations], such as [具体例子], demonstrate [similar pattern], which suggests [deeper principle].'

  • 列数字

    P2

    在 第2段 中，作者使用了 '35 healthy people'、'two nights'、'more than twice as long' 这些 quantitative data 来增强 research findings 的 credibility。这些 precise numbers 让 the first-night effect 从 subjective feeling 变成 measurable phenomenon，strengthens the scientific validity of the conclusion that brain hemispheres behave asymmetrically during unfamiliar sleep。

    信号词 percent times approximately nearly over less than around

    仿写： 在描述 research results 或 comparisons 时，主动寻找能够 quantify 的 aspects。不要只说 'participants slept poorly'，而要说 'took X times longer to fall asleep' 或 'slept Y% less overall'。模版：'The study involved [数字] participants who [action]. Results showed [数字/倍数] difference in [指标], indicating [conclusion].'

  • 作比较

    P2 P3

    文中多处运用 comparison：在 第2段 比较了 first night vs. second night 的 sleep quality，以及 left hemisphere vs. right hemisphere 的 sleep depth；在 第3段 比较了 irregular beeps vs. regularly timed beeps 的 brain response。这些 contrasts 清晰地展现了 the first-night effect 的 specific manifestation，证明 one hemisphere stays more alert，directly supports the thesis about evolutionary protective mechanism。

    信号词 less well more than than while whereas in contrast compared to unlike similarly different from as opposed to

    仿写： 在 analyzing phenomena 时，寻找 natural pairs for comparison：before vs. after、experimental group vs. control group、different conditions 下的 responses。用 parallel structure 强化 contrast。模版：'While [A] showed [characteristic 1], [B] demonstrated [characteristic 2], suggesting that [interpretation]. This difference between [A] and [B] indicates [deeper meaning].'

  • 下定义

    P1

    在 第1段 开篇，作者定义了 'first-night effect'：人们在 unfamiliar surroundings 的 different bed 中常常 experience trouble sleeping 这个 phenomenon 被称为 'first-night effect'。这个 clear definition 为整篇文章 establishes the topic and scope，让 readers immediately understand what will be explored，serves as the foundation for subsequent scientific investigation into its evolutionary origins。

    信号词 is a phenomenon known as is defined as refers to means is can be described as is called known as termed

    仿写： 在 introducing unfamiliar terms 或 technical concepts 时，立即提供 definition。可以用 'is defined as'、'refers to'、'is known as' 等 expressions。模版：'[Term] is a phenomenon/concept that [defining characteristics]. It refers to [具体说明], which [further clarification if needed].'

  • 作诠释

    P2 P3

    在 第2段 中，'This led her to wonder if people might be doing the same thing' 这句对前面的 birds and dolphins example 进行了 interpretation，说明 Dr. Sasaki 如何从 animal behavior 推导出关于 humans 的 hypothesis。这个 interpretation 连接了 existing knowledge 和 new research direction，解释了 the logic behind the study design，helps readers understand the reasoning process that supports the main thesis。

    信号词 This led her to wonder this suggests this indicates this means implying that which suggests indicating that the implication is in other words

    仿写： 在 presenting evidence 之后，主动添加 interpretive sentences 来 explain the significance。用 'this suggests'、'this indicates'、'this led to' 等 phrases 引导。模版：'[Evidence/observation]. This suggests/indicates that [interpretation], which [connection to larger point]. The implication is [deeper meaning].'

IMPLIED MEANING · 言外之意

5 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。

  • 首夜效应的演化优势存在矛盾

    P2
    The puzzle was what benefit would be gained from it when performance might be affected the following day.

    问题词 puzzle problem paradox contradiction dilemma mystery enigma

    这里的 puzzle 暗示 first-night effect 看起来 counterproductive，因为 sleep poorly 会 affect next day's performance。这个 implied contradiction 其实是 Dr. Sasaki's research motivation。言外之意是：既然 evolution 不会 preserve disadvantageous traits，那这个 effect 必定有 hidden benefit。这为后文揭示 hemispheric asymmetry 作为 protective mechanism 铺垫了 logical foundation，让读者理解为什么需要这个 research。

  • 动物的半脑睡眠启发人类研究假设

    P2
    She also knew from previous work conducted on birds and dolphins that these animals put half of their brains to sleep at a time so that they can rest while remaining alert enough to avoid predators. This led her to wonder if people might be doing the same thing.

    因果推理类 This led her to wonder if This led to This made her wonder This suggested that This prompted This raised the question thereby leading to

    这个 "led her to wonder" 的言外之意是：人类的 first-night effect 可能不是 random quirk，而是 share the same evolutionary logic 像 birds and dolphins 一样。通过建立这个 cross-species parallel，作者暗示 hemispheric asymmetry 是 conserved survival strategy。这对文章主旨至关重要，因为它 transform the puzzle from a human-specific oddity 变成 a broader evolutionary adaptation，从而 provide theoretical framework 为后续的 experimental findings 提供理论支撑。

  • 实验设计体现预期验证逻辑

    P2
    Dr. Sasaki found, as expected, the participants slept less well on their first night than they did on their second

    预期确认类 as expected as predicted unsurprisingly predictably as anticipated not surprisingly as hypothesized

    这个 "as expected" 暗示 poor first-night sleep 只是 baseline confirmation，不是研究的 real discovery。言外之意是：接下来的内容才是 the crucial finding。果然，紧接着作者 reveal hemispheric asymmetry，这才是 central evidence。这个表达对文章主旨的作用是 structure the logic：通过 downplay obvious results，作者 guide readers' attention 到真正的 breakthrough，即 the left hemisphere stays more alert。这种 rhetorical move 确保读者不会 mistake superficial observations for the actual mechanism。

  • 实验重设计验证因果机制

    P3
    Curious if the left hemispheres were indeed remaining awake to process information detected in the surrounding environment, Dr. Sasaki re-ran the experiment

    进一步探究类 Curious if To test whether Wondering whether To determine if To verify that To confirm whether Seeking to understand if

    这个 "Curious if" 的言外之意是：之前发现的 hemispheric asymmetry 只是 structural observation，还需要 functional evidence 来证明 left hemisphere 确实在 actively monitoring environment。通过 introduce irregular beeps，研究 test a specific prediction：如果 left hemisphere 真的在 keeping guard，它应该 selectively respond to unexpected stimuli。这个 二次实验 对文章主旨至关重要，因为它 transform the finding from correlation 到 causation，conclusively demonstrate 这是 protective vigilance mechanism 而非 random brain activity pattern。

  • 实验预测与结果完全吻合

    P3
    if the left hemisphere was staying alert to keep guard in a strange environment, then it would react to the irregular beeps by stirring people from sleep and would ignore the regularly timed ones. This is precisely what she found.

    精确验证类 This is precisely what she found precisely exactly what just as predicted perfectly aligned confirmed exactly matched predictions perfectly

    这个 "precisely" 的言外之意是：实验不仅 support the hypothesis，而且 the match is so exact 以至于 alternative explanations 基本被排除。言外之意传达了 scientific certainty：first-night effect 确实是 vigilance mechanism。对文章主旨而言，这是 culminating evidence，它 definitively answer the initial puzzle—为什么 evolution 会 preserve 一个看似 impair sleep 的 trait。答案是：short-term sleep quality 被 sacrifice 来 gain critical threat detection，这是 survival-oriented trade-off。这个 precise confirmation 让整个 argument come full circle。

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（ Objectively explanatory with scientific curiosity）。下面是按步骤还原的判断过程与文中的态度信号词。

  1. 识别文章开篇的陈述性定义 P1

    说明文的 primary purpose 通常是 inform 或者 explain，而非 persuade 或 criticize。如果 opening 部分用的是 neutral descriptive terms 来 introduce a topic，基本可以判断作者采取的是 objective stance。这种 informative tone 是说明文最典型的 stylistic feature。

  2. 统计研究动词的中性程度 P2 P3

    说明文作者如果保持 neutral stance，他们会 focus on describing what researchers did 和 what they discovered，用的 verbs 都是 factual action verbs。如果作者想 express approval 或 disapproval，就会 insert evaluative language 比如「brilliantly discovered」或「failed to recognize」。这篇文章完全没有这类 loaded language。

  3. 区分数据陈述与主观解读 P2 P3

    在说明文中，作者对 research results 的 presentation style 最能 reveal their attitude。Objective authors 会 let the data speak for itself，用 precise measurements 和 factual descriptions。如果作者开始 add interpretive layers 或 make broad claims beyond the data，那就 shift away from neutrality。这篇文章严格 stick to what the study actually showed。

  4. 评估全文论述的平衡性 P1 P2 P3

    说明文的 overall tone 应该 exhibit intellectual curiosity without advocacy。如果作者 present multiple perspectives，acknowledge limitations，且 maintain consistent neutrality throughout，那就是 genuinely objective。这篇文章的 structure 本身就 demonstrate 这种 balanced inquiry：提出 puzzle，探索 possible mechanisms，验证 hypothesis，每一步都是 logical progression 而非 argumentative buildup。

文中的态度信号词

  • phenomenon known as P1

    这个 phrase「phenomenon known as」是典型的 definitional language，作者在 objectively label 一个 scientific observation。说明文中用这类 neutral terminology 来 introduce topics，表明作者的 role 是 educator 而非 advocate，他们在 presenting established knowledge 而不是 pushing personal views。

    同类词 effect is called refers to is defined as term

  • set out to investigate P2

    「set out to investigate」这个 verb phrase 是 scholarly discourse 的标准用语，表明作者在 describing research methodology objectively。这类 phrases 在说明文中 function as procedural markers，作者在 chronicling the scientific process 而非 evaluating its worth。The choice of「investigate」over「prove」或「expose」reveals non-judgmental reporting。

    同类词 aimed to explore sought to understand examined studied analyzed

  • probably P2

    Modal word「probably」表明作者在 acknowledging uncertainty，这是 scientific objectivity 的重要 marker。说明文作者用这类 hedging language 来 avoid overstating claims，showing intellectual honesty。Instead of presenting speculation as fact，作者用「probably」to signal 这是 reasonable inference 而非 proven conclusion。

    同类词 likely possibly may might could

  • as expected P2

    Phrase「as expected」shows 作者在 relating findings to prior hypotheses objectively。这不是在 celebrate 结果，而是在 factually note alignment with predictions。说明文中这类 phrases serve to connect observations to theoretical frameworks without adding emotional color。作者 maintain neutrality by simply acknowledging correspondence。

    同类词 as predicted consistent with in line with confirming supporting

  • precisely P3

    「Precisely」这个 adverb 在这里 emphasize 实验结果与 prediction 的 exact match，但它的 tone 仍然是 factual 而非 triumphant。作者在 underscore the accuracy of hypothesis confirmation，这是 scientific rigor 的 marker。说明文中用这类 precision markers 来 highlight methodological soundness 而非 personal satisfaction。

    同类词 exactly specifically accurately correspondingly accordingly

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，可直接迁移到其他英语四级 真题文章。

如何快速判断这是一篇说明文？

  1. 开头定义现象 P1

    本文第一段直接介绍了 first-night effect 这个 phenomenon,用 is known as 这种定义性语言来 describe 客观现象,这是 expository writing 的典型特征,而议论文会提出 argument 或 claim,新闻报道会用 happened 或 announced 等词汇报道 recent events

  2. 详述研究过程 P2

    第二段出现了 Dr. Sasaki and her colleagues、her team studied、participants 等表述,展示了完整的 research methodology 和 experimental design,这是 scientific explanation 的标志,议论文不会详述 research procedures,新闻报道只会 summarize results 而不会深入 describe methodology

  3. 追加验证实验 P3

    第三段用 Curious if 开头,描述了 Dr. Sasaki re-ran the experiment 并设计了新的 testing conditions,这种 iterative research approach 是说明文 explaining scientific discoveries 的特点,议论文会 move to different arguments 而非 repeat experiments,新闻不会有这种 detailed follow-up

  4. 解释工作原理 P1 P2 P3

    本文从始至终都在 explain first-night effect 的 biological mechanism,使用 descriptive 和 analytical language 而非 evaluative 或 opinionated expressions,没有出现 should、must、it is important that 等 argumentative markers,也没有 yesterday、recently、announced 等 news indicators,整体 tone 是 educational 而非 persuasive 或 informative-journalistic

哪些词暴露了说明文体裁？

  • phenomenon known as P1 说明对象定义解释词 is called is defined as refers to is termed is described as
  • set out to investigate P1 说明顺序与例证词 conducted research on studied examined analyzed explored
  • The puzzle was P2 说明顺序与例证词 The question was The challenge was The problem was The issue was The mystery was
  • This led her to wonder if P2 说明顺序与例证词 This prompted the question of whether This raised the possibility that This suggested that This made them consider whether This caused researchers to hypothesize
  • To take a closer look P2 说明顺序与例证词 To investigate further To examine this To test this hypothesis To explore this question To verify this
  • were carefully monitored with techniques that P2 事物属性功能描述词 were carefully monitored with were measured using were tracked through were observed with were assessed by
  • as expected P2 说明顺序与例证词 as predicted as anticipated as hypothesized consistent with predictions in line with expectations
  • behaved in a similar manner seen in P2 事物属性功能描述词 showed patterns similar to exhibited behavior comparable to displayed characteristics like functioned similarly to operated in a way resembling
  • Curious if P3 说明顺序与例证词 Wondering whether To determine if To see whether Interested in knowing if Seeking to understand whether
  • She worked out that, if... then P3 说明顺序与例证词 worked out that if... then reasoned that if... then hypothesized that if... then predicted that if... then theorized that if... then
  • This is precisely what she found P3 说明顺序与例证词 This is exactly what occurred This is what the results showed This is indeed what happened The findings confirmed this The results matched this prediction
SENTENCE INSIGHTS · 句子精讲

6 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 2017年12月英语四级真题第1套 Part III Section C (1) 的常见问题

2017年12月英语四级真题第1套 Part III Section C (1) 文章的主旨是什么？
佐佐木博士的研究揭示了"首夜效应"的产生原因:在陌生环境中,大脑的一侧半球会保持更高的警觉性,类似于鸟类和海豚,这是一种进化形成的保护机制,用于在新环境中睡眠时防范潜在威胁。（英文表述：Research by Dr. Sasaki reveals that the first-night effect occurs because one brain hemisphere remains more alert in unfamiliar environments, similar to birds and dolphins, serving as an evolutionary protective mechanism against potential threats while sleeping in new surroundings.）
2017年12月英语四级真题第1套 Part III Section C (1) 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（Objectively explanatory with scientific curiosity）。CEFR 难度 C1，全文 349 词、3 段；在英语四级全部 511 篇真题文章中，C1 级共 163 篇（占 32%）。
2017年12月英语四级真题第1套 Part III Section C (1) 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——引入研究现象与研究者；第2段——研究假设、方法与初步发现；第3段——验证性实验与结论确认。
2017年12月英语四级真题第1套 Part III Section C (1) 文章的作者态度是什么？
作者态度是客观中立（Objectively explanatory with scientific curiosity）。判断路径：识别文章开篇的陈述性定义 → 统计研究动词的中性程度 → 区分数据陈述与主观解读 → 评估全文论述的平衡性；文中的态度信号词包括 phenomenon known as（第1段）、set out to investigate（第2段）、probably（第2段）、as expected（第2段）、precisely（第3段）。
2017年12月英语四级真题第1套 Part III Section C (1) 文章中有哪些值得积累的生词？
按文中出现顺序共 4 个：soundly（熟睡地、酣睡地）、predator（捕食者、食肉动物）、hemisphere（半球）、stir（唤醒、惊动、使离开某种状态），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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