Unit 5 A delicate world（复习讲义）英语外研版选择性必修第二册

该高中英语复习讲义围绕“脆弱生态系统”主题构建知识体系，通过表格梳理两篇核心语篇的因果链、时间轴及主题意义，用“教材语境-搭配易错-迁移应用”结构精讲10个高价值词汇，借助对比表格区分形式宾语it与其他it用法，清晰呈现生态变化分析、形式宾语应用等重难点的内在联系。 讲义亮点在于“语篇分析-词汇迁移-语法应用-写作输出”的闭环设计，如词汇即时小练通过decrease的by/to搭配训练语言能力，形式宾语it判断流程培养思维品质，微写作要求用2处it和证据提升学习能力。分层练习覆盖基础到综合，助力不同学生巩固，教师可依托学情诊断实施精准复习教学。

外研版选择性必修第二册Unit 5 A delicate world（复习讲义） 复习要点 理解脆弱生态系统中的因果联系；复盘两篇核心语篇；掌握10个高价值词汇和形式宾语it；完成讲座稿迁移。 复习重难点 重点：用教材语言解释生态变化并表达保护建议。难点：区分干预的直接结果与连锁后果，并把形式宾语it用于真实表达。 学情诊断 常见问题：只背中文义；混淆by/to和词形；把生态事件看成单一因果；遗漏it或真正宾语；讲座只有口号、缺少证据。 一、单元语篇复盘：从生态失衡走向系统修复 1. MACQUARIE ISLAND: from Chaos to Conservation 语篇类型与视角 按时间推进的生态修复叙事；叙述者以保护工作者视角回顾人类介入的连锁后果。 核心因果链 外来物种进入 → 捕食与植被破坏 → 局部治理引发新失衡 → 认识到必须整体治理。 时间轴抓手 1810人类到来；19世纪末引入兔子；20世纪后期多次控制；2000猫被清除；2006出现严重后果；2014综合治理宣告成功。 主题意义 生态系统是关系网；善意行动也可能产生非预期结果，保护必须依据证据、统筹物种并持续监测。 【关键结构】用时间标记恢复事件顺序，用cause—effect链解释每次干预为何改变下一环节。 【课堂追问】Why did solving one problem sometimes create another on Macquarie Island? 【参考】Because each species was connected to others. Removing one pressure changed food and shelter relationships, so a local solution could shift the imbalance elsewhere. 2. WHY SHENNONGJIA? 语篇类型与目的 讲座稿；回答“神农架为何入选世界遗产名录”，并说明保护价值。 结构路径 问候与设问 → 两项入选理由 → 数据、例子与比较 → 人与自然和谐相处 → 总结与问答。 证据组织 海拔差异说明环境多样；物种数据支撑生物多样性；金丝猴与本土蜜蜂例子呈现具体保护行动。 主题意义 真正的保护既维护生物与生态过程，也尊重当地居民长期形成的可持续生活方式。 【课堂追问】How do data, examples and comparisons make the lecture more convincing? 【参考】Data show scale, examples make protection concrete, and comparisons help the audience see why the evidence matters. Together they turn a claim into a reasoned argument. 【迁移任务】用一句话比较两篇语篇的保护路径：Macquarie Island emphasizes ______, while Shennongjia highlights ______. 【示例】Macquarie Island emphasizes learning from unintended consequences, while Shennongjia highlights evidence-based protection and coexistence with local people. 知识点1：核心词汇精讲 decrease：数量下降与变化幅度 【教材语境】教材语境中，病毒使兔子的数量下降；该词既可作动词，也可作名词。 【搭配与易错】decrease by + 幅度；decrease to + 终点；on the decrease 正在减少。reduce通常是及物动词，强调“使……减少”。 【迁移例句】Restoration reduced soil loss, and the amount of bare ground decreased steadily. 【即时小练】After the new rule, plastic waste decreased ______ 30% ______ 21 tonnes. 【答案与诊断】by; to。by说明变化幅度，to说明变化后的终点。 trap：受困、困住与诱使 【教材语境】教材用 be trapped in 描写动物或人被困在危险环境中。 【搭配与易错】trap vt./n.；be trapped in 被困在；trap sb into doing sth 诱使某人做某事。trapped是规则双写形式。 【迁移例句】Discarded fishing line can trap seabirds and prevent them from feeding. 【即时小练】Rescuers freed two birds ______ (trap) in fishing line. 【答案与诊断】trapped。过去分词短语作后置定语，表示被动。 explode：爆炸与数量激增 【教材语境】教材把 rabbit numbers exploded 用作“数量激增”，而非真实爆炸。 【搭配与易错】explode vi.；explosion n.；an explosion in numbers 数量激增；explode with anger / into laughter 表示情绪突然爆发。 【迁移例句】Once predators disappeared, the rabbit population exploded and vegetation suffered. 【即时小练】Without natural enemies, the population ______ (explode), causing an ecological crisis. 【答案与诊断】exploded。语境叙述过去发生的数量激增。 collapse：倒塌、崩溃与生态失衡 【教材语境】教材用该词描述斜坡或生态系统因长期破坏而突然失去支撑。 【搭配与易错】collapse vi./n.；a slope / system collapses；collapse into a chair。fall强调落下，collapse强调结构或系统整体失去支撑。 【迁移例句】If plant roots disappear, the bank may collapse after heavy rain. 【即时小练】The damaged bank ______ after the storm, but the team did not let the project collapse. 【答案与诊断】collapsed。第一空叙述过去事件，第二个collapse为原形。 substantial：数量大、程度显著 【教材语境】教材用 a substantial number of 强调保护行动涉及的数量可观。 【搭配与易错】substantial adj. 可表示“大量的、重大的、结实的”；a substantial number of + 复数名词。近义词significant侧重重要或统计意义。 【迁移例句】The reserve made substantial progress, but complete recovery still required time. 【即时小练】A ______ number of volunteers provided ______ support. (substance) 【答案与诊断】substantial; substantial。两空均需形容词修饰名词。 intervention：介入与干预 【教材语境】两篇语篇都提醒读者：human intervention既可能造成破坏，也可能修复生态。 【搭配与易错】intervention n.；intervene vi.；intervene in a crisis。interfere常带“妨碍、不当干涉”意味，语气更负面。 【迁移例句】Good intervention begins with evidence and includes follow-up monitoring. 【即时小练】The ecologist argued that people should ______ only after careful observation. (intervention) 【答案与诊断】intervene。情态动词should后用动词原形。 owe：归因、欠与责任 【教材语境】教材用 owe...to...把生态恢复归因于长期、系统的保护行动。 【搭配与易错】owe A to B 把A归因于B；owe sb sth 欠某人某物；owe it to sb that... 多亏某人……；owing to 因为。 【迁移例句】We owe the wetland's recovery to residents who monitored it for years. 【即时小练】We owe the recovery ______ local residents, and we owe it to them ______ keep monitoring. 【答案与诊断】to; to。前者是owe A to B，后者是不定式表示应尽责任。 comparison：比较与对照证据 【教材语境】WHY SHENNONGJIA? 使用数据、例子和比较，使讲座理由更有说服力。 【搭配与易错】make/draw a comparison between；by/in comparison with；compare A with B（比较异同）；compare A to B（比作）。 【迁移例句】A comparison between old and new photographs made the recovery visible. 【即时小练】The report made a ______ between two restoration methods. (compare) 【答案与诊断】comparison。冠词a后需要可数名词单数。 apparently：表面看来与证据限度 【教材语境】教材用 apparently 表示“根据现有迹象看来”，保留判断余地。 【搭配与易错】apparently adv.；apparent adj.；It is apparent that...。obviously语气更强，表示“显然”；apparently常暗示信息来自观察或转述。 【迁移例句】The lake is apparently clean, but chemical tests reveal excess nutrients. 【即时小练】The lake is ______ clean, but tests still show excess nutrients. (apparent) 【答案与诊断】apparently。修饰形容词clean和整句判断，需要副词。 secure：安全的、获得与巩固 【教材语境】教材把 secure home 与物种能够长期生存的稳定栖息地联系起来。 【搭配与易错】secure adj./vt.；a secure habitat；feel secure；secure funding / support；security n.。safe强调免受眼前危险，secure更强调稳定、可靠。 【迁移例句】Native plants secure the soil and provide a secure home for insects. 【即时小练】The project aims to provide a ______ habitat and improve water ______. (secure) 【答案与诊断】secure; security。第一空形容词修饰habitat，第二空名词作宾语。 知识点2：话题表达与语篇迁移 生态变化与保护表达链 表达功能 核心表达 迁移句型 描述失衡 upset the ecological balance; alien species; out of control Introducing one species may upset the ecological balance and trigger unexpected change. 呈现后果 soil erosion; habitat loss; on the decrease; in consequence Vegetation was damaged; in consequence, nesting areas became less secure. 解释联系 food web; coexist with; depend on; contribute to Each species contributes to a network on which the whole ecosystem depends. 说明行动 remove a threat; monitor change; restore a habitat; once and for all A lasting solution must remove the threat and monitor the system as a whole. 提供证据 according to data; for example; by comparison By comparison with earlier photographs, the recovery is substantial. 升华主题 in harmony with nature; a shared responsibility Conservation works best when people live in harmony with nature and accept shared responsibility. 【运用原则】先写清“变化—原因—后果—行动—证据”，再选择表达；不要把主题词孤立堆砌。 【迁移训练】围绕“Why must conservation be evidence-based?”写3句话：提出观点、给出例子、形成结论。 【示例】Conservation must be evidence-based because ecosystems contain hidden connections. On Macquarie Island, removing one species changed the pressure on others. Therefore, every intervention should be tested and followed by long-term monitoring. 知识点3：形式宾语it与讲座稿写作 形式宾语it：观察—比较—归纳—判断—运用 【观察】No visitors would think it surprising that the island is a UNESCO World Heritage Site. 【观察】Experts felt it necessary to come up with a plan. 【发现】两句均由it占据宾语位置；真正宾语分别是that从句和to do不定式。 比较维度 形式宾语it 指代性it / 形式主语it 位置与功能 位于谓语后，先占宾语位置；后置真正宾语。 指代性it有明确所指；形式主语it位于句首。 基本结构 V + it + adj./n. + to do / that... It + be + adj. + to do / that... 常见动词 find, think, feel, consider, make, believe 指代性it可跟普通及物动词；形式主语常跟be。 固定结构 owe it to sb that...; take it for granted that...; see to it that... like/hate/appreciate it when/if...中的it也先占宾语位置。 【判断流程】①谓语后是否需要宾语 → ②it后是否有宾补 → ③句尾是否出现to do/that从句 → ④能否把真正宾语前移。 【高频错误】漏写it；把it与真正宾语同时删掉；在make it possible后误用doing；把所有it都解释为“它”。 即时训练 1. We find ______ difficult to predict every consequence of an intervention. 2. New technology makes it possible ______ (monitor) animals without disturbing them. 3. I would appreciate ______ if you could join the wetland survey. 4. Do not take it for granted ______ a green landscape is already healthy. 5. 改错：The team considered was necessary to collect more evidence. 6. 合并：We believe this. Long-term monitoring can prevent small risks from growing. 【答案】1. it；2. to monitor；3. it；4. that； 5. considered后加it：The team considered it necessary to collect more evidence. 6. We believe it possible for long-term monitoring to prevent small risks from growing. / We believe it important that long-term monitoring can prevent small risks from growing. 单元写作：Drafting a lecture 讲座环节 内容任务 语言支架 问候与主题 问候听众；提出地点或问题。 Good morning... Today I would like to explain why... 理由与证据 用数据、例子或比较说明价值。 According to... / For example... / By comparison... 行动与意义 说明保护措施及人与自然关系。 We consider it essential to... / This makes it possible for... 总结与问答 回扣观点；提出倡议；结束。 All of this explains why... Thank you. Any questions? 【写作提纲】Topic/Problem: ______　Reason/Evidence: ______　Action: ______　Call: ______ 【自检】□80—100词　□至少2处形式宾语it　□含数据/例子/比较　□讲座开头与结尾完整 【课堂迁移】用50—60词比较Macquarie Island与Shennongjia的保护路径，并至少使用1处形式宾语it。 【示例】Macquarie Island shows why people must repair damage caused by introduced species, while Shennongjia highlights the value of protecting biodiversity together with local ways of life. Both cases make it clear that conservation depends on evidence and cooperation. We consider it essential to monitor change instead of treating one action as the end. （建议用时：45分钟　满分：60分　共34题） 一、语境词汇（每题1分，共8分） 1. After protective fencing, the deer population began to ______ steadily rather than rise. (decrease) 2. The young seal was ______ between rocks by the rising tide. (trap) 3. With food abundant and no predators, rabbit numbers ______ within a few years. (explode) 4. Heavy rain caused part of the damaged slope to ______. (collapse) 5. The reserve has made ______ progress in restoring native vegetation. (substance) 6. Early human ______ upset the island's ecological balance. (intervene) 7. The recovery is largely ______ to years of patient monitoring. (owe) 8. A ______ between old and new photographs reveals how much the habitat has changed. (compare) 【答案点拨】1. decrease：begin to后接动词原形。 2. trapped：be trapped表示“被困”。 3. exploded：within a few years与语境共同指向过去时。 4. collapse：cause sb/sth to do结构中用动词原形。 5. substantial：形容词修饰progress。 6. intervention：形容词human后接名词。 7. owed：be owed to表示“归因于”。 8. comparison：冠词A后接可数名词单数。 二、语法与句式迁移（每题2分，共12分） 9. Experts found ______ necessary to study the whole food web before acting. 10. The new sensors make it easier for scientists ______ (monitor) rare animals. 11. We owe it to local volunteers ______ the bee population has remained secure. 12. Do not take it for granted ______ every intervention will produce the intended result. 13. 改写：The team believed that restoring the wetland was possible.（用形式宾语it） ________________________________________________________________________________ 14. 翻译：我们认为每次行动后持续监测生态系统十分重要。（consider it...） ________________________________________________________________________________ 【答案点拨】9 it。find + it + adj. + to do，it为形式宾语。 10 to monitor。make it + adj. + for sb + to do。 11 that。owe it to sb that...为固定结构。 12 that。take it for granted that...意为“想当然地认为……”。 13 The team believed it possible to restore the wetland. 原that从句转换为it + 宾补 + 不定式。 14 We consider it essential to keep monitoring the ecosystem after every action. 也可用that从句作真正宾语。 三、阅读理解（每题2.5分，共10分） When “No Pests” Is Only the Beginning In 2014, Macquarie Island was declared free of rabbits, rats and mice after an ambitious eradication programme. For decades, these introduced mammals had eaten native plants, damaged nesting areas and changed relationships across the food web. Removing them was a major success, but scientists did not treat the announcement as the end of the story. Ten years later, researchers returned to examine what recovery actually looked like. The most obvious change was green: tall grasses and other native plants had spread across places that had once been closely grazed. Old photographs made the contrast dramatic. Yet the team also looked beyond attractive scenery. Recovering vegetation can provide shelter, hold soil in place and create conditions in which insects and seabirds can thrive. A change in one part of the system may therefore support several others. The researchers compared new observations with a baseline collected before and during the eradication work. They studied fixed vegetation plots, repeated photographs and records of animal activity. Such evidence matters because species do not all respond at the same speed. Some plants return quickly, while slower-growing communities may need many years. Animals may also wait until suitable food and nesting cover are secure. A single visit could easily miss these different timelines. Success has brought another responsibility: prevention. Ships, equipment and visitors can accidentally carry seeds, insects or disease to a remote island. Careful checks may seem less exciting than a large rescue operation, but they reduce the chance that the same kind of damage will begin again. Long-term monitoring also helps managers notice an unexpected change before it grows out of control. Macquarie Island shows that restoration is not a rewind button. People cannot simply remove a threat and expect every relationship to return immediately. A better measure of success is whether the ecosystem is rebuilding its connections and becoming able to face future pressure. That requires patience, evidence and the willingness to keep learning after the headlines have faded. 15. What did the researchers' return visit mainly reveal? A. The island's landscape had remained almost unchanged. B. Native vegetation had visibly recovered in many places. C. Visitors had become the island's greatest attraction. D. Long-term monitoring was no longer necessary. 16. What does the word "baseline" in paragraph 3 most probably mean? A. A starting set of measurements used for later comparison. B. A legal boundary around a protected area. C. A fence that prevents animals from entering. D. A final score given to a conservation project. 17. What can be inferred from the passage? A. A restored ecosystem never needs further human attention. B. Removing pests guarantees that all species recover together. C. Conservation must continue after the main action has succeeded. D. Attractive scenery is sufficient evidence of full recovery. 18. How is the passage mainly developed? A. By listing instructions for tourists in time order. B. By revisiting a success and drawing a wider lesson from it. C. By comparing the climates of two distant islands. D. By arguing that eradication programmes should be stopped. 【答案解析】 15. B 定位第2段：最直观的变化是本土植被重新扩展；A、C、D均与原文相反或无依据。 16. A 第3段说明研究者把新观察与行动前后的资料比较，baseline即后续比较的起始数据。 17. C 第4、5段强调预防、长期监测与持续学习；B把“必要条件”夸大为“充分条件”。 18. B 文章先回访十年前的治理成果，再从恢复速度、预防和监测提炼更广泛的保护启示。 四、完形填空（每题1分，共15分） A Small Wetland, A Long Lesson When students at Greenbank School began restoring a small wetland, they 19 ______ the job would be simple: remove rubbish and make the water look clean. Their biology teacher asked them to wait. A wetland, she explained, is not a garden whose success can be judged 20 ______ by appearance. Healthy water must support plants, insects and birds, not merely please the eye. First, the team mapped how water moved through the area. They measured sunlight, water depth and oxygen for two weeks before changing anything. Rather than treating the algae as the problem itself, they looked for the 21 ______ of the extra nutrients. Rainwater 22 ______ fertilizer from nearby lawns entered the pond through a drain. The students placed signs beside the drain and persuaded the school to 23 ______ fertilizer use. They also left part of the bank unmown, 24 ______ native plants to return. Progress was 25 ______ than expected. After one storm, the water turned brown, and several students called the plan a 26 ______ . 27 ______ , tests showed that oxygen levels were improving. The muddy colour 28 ______ from freshly exposed soil, not from a collapse of the ecosystem. Within weeks, plant roots 29 ______ the bank; insects appeared, and birds 30 ______ . The return of these visitors suggested that food and shelter were rebuilding together. Most importantly, the team changed how it measured success. 31 ______ asking whether the pond looked perfect, students recorded oxygen levels, plant variety and visits by birds. This made it 32 ______ to notice small improvements and respond to new 33 ______ . The project taught them that conservation is not a single dramatic act. It is a process of understanding connections, testing decisions and correcting course before a small problem grows out of control. 19. A. assumed B. denied C. forgot D. proved 20. A. only B. seldom C. already D. nearly 21. A. source B. size C. colour D. cost 22. A. carrying B. refusing C. comparing D. securing 23. A. reduce B. record C. trap D. explode 24. A. allowing B. warning C. forcing D. expecting 25. A. slower B. safer C. stranger D. louder 26. A. failure B. comparison C. departure D. greeting 27. A. Yet B. Therefore C. Besides D. Similarly 28. A. came B. prevented C. borrowed D. owed 29. A. secured B. dissolved C. collapsed D. multiplied 30. A. followed B. escaped C. apologised D. hesitated 31. A. Instead of B. Owing to C. Apart from D. In return for 32. A. possible B. rare C. mysterious D. rough 33. A. risks B. lectures C. sessions D. criteria 【答案解析】 19. A assumed 学生起初“认为”任务很简单。 20. A only only by appearance与后文“不能只看外观”呼应。 21. A source 不是把藻类当作问题本身，而是追查营养物来源。 22. A carrying 现在分词修饰rainwater，表示雨水携带肥料。 23. A reduce 与fertilizer use构成自然搭配。 24. A allowing 结果状语：不割草使本土植物得以返回。 25. A slower than expected要求比较级，且下文显示恢复并不迅速。 26. A failure 水变褐使部分学生误判方案失败。 27. A Yet 检测结果改善，与前句表面现象构成转折。 28. A came come from表示“来自、由……造成”。 29. A secured 植物根系稳固河岸；其余选项不合语义。 30. A followed 昆虫出现后，鸟类随之而来，体现食物网联系。 31. A Instead of 评价标准由“外观完美”转向多项生态指标。 32. A possible make it possible to do为形式宾语结构。 33. A risks 监测用于发现改善并应对新的风险。 五、微写作（15分） 34. 假定你是校环保社团代表，请为校园“世界环境日”活动写一篇80—100词英文微型讲座稿，介绍一个脆弱生态系统面临的问题、保护理由、具体行动和结尾倡议；至少使用2处形式宾语it，并至少使用一项数据、例子或对比作为证据。 ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 【评分标准】内容5分：问题、理由、行动、倡议完整且证据具体；结构3分：讲座开头、展开、结尾清楚；语言5分：准确并至少使用2处形式宾语it；书写与规范2分。 【参考范文】 Good morning, everyone. Today I want to talk about the wetland beside our school. Litter and excess nutrients have made it difficult for native plants to thrive. We consider it essential to protect the wetland because it stores rainwater and provides a secure home for birds and insects. Last month, volunteers removed twelve bags of rubbish, and we found it encouraging that kingfishers returned soon afterwards. However, one clean-up is not enough. Please reduce plastic use, keep fertilizer away from drains and join our monthly survey. Small actions can restore a delicate world. Thank you. 【教师点拨】先检查交际体裁和四项内容，再圈出形式宾语结构及证据；若只有口号而无事实或行动，内容与论证均应扣分。 6 原创精品资源学科网独家享有版权，侵权必究！ 1 学科网（北京）股份有限公司 $ 外研版选择性必修第二册Unit 5 A delicate world（复习讲义） 复习要点 理解脆弱生态系统中的因果联系；复盘两篇核心语篇；掌握10个高价值词汇和形式宾语it；完成讲座稿迁移。 复习重难点 重点：用教材语言解释生态变化并表达保护建议。难点：区分干预的直接结果与连锁后果，并把形式宾语it用于真实表达。 学情诊断 常见问题：只背中文义；混淆by/to和词形；把生态事件看成单一因果；遗漏it或真正宾语；讲座只有口号、缺少证据。 一、单元语篇复盘：从生态失衡走向系统修复 1. MACQUARIE ISLAND: from Chaos to Conservation 语篇类型与视角 按时间推进的生态修复叙事；叙述者以保护工作者视角回顾人类介入的连锁后果。 核心因果链 外来物种进入 → 捕食与植被破坏 → 局部治理引发新失衡 → 认识到必须整体治理。 时间轴抓手 1810人类到来；19世纪末引入兔子；20世纪后期多次控制；2000猫被清除；2006出现严重后果；2014综合治理宣告成功。 主题意义 生态系统是关系网；善意行动也可能产生非预期结果，保护必须依据证据、统筹物种并持续监测。 【关键结构】用时间标记恢复事件顺序，用cause—effect链解释每次干预为何改变下一环节。 【课堂追问】Why did solving one problem sometimes create another on Macquarie Island? ________________________________________________________________________________________________________________________________________________________________________________________2. WHY SHENNONGJIA? 语篇类型与目的 讲座稿；回答“神农架为何入选世界遗产名录”，并说明保护价值。 结构路径 问候与设问 → 两项入选理由 → 数据、例子与比较 → 人与自然和谐相处 → 总结与问答。 证据组织 海拔差异说明环境多样；物种数据支撑生物多样性；金丝猴与本土蜜蜂例子呈现具体保护行动。 主题意义 真正的保护既维护生物与生态过程，也尊重当地居民长期形成的可持续生活方式。 【课堂追问】How do data, examples and comparisons make the lecture more convincing? ________________________________________________________________________________________________________________________________________________________________________________________【迁移任务】用一句话比较两篇语篇的保护路径：Macquarie Island emphasizes ______, while Shennongjia highlights ______. ________________________________________________________________________________________________________________________________________________________________________________________知识点1：核心词汇精讲 decrease：数量下降与变化幅度 【教材语境】教材语境中，病毒使兔子的数量下降；该词既可作动词，也可作名词。 【搭配与易错】decrease by + 幅度；decrease to + 终点；on the decrease 正在减少。reduce通常是及物动词，强调“使……减少”。 【迁移例句】Restoration reduced soil loss, and the amount of bare ground decreased steadily. 【即时小练】After the new rule, plastic waste decreased ______ 30% ______ 21 tonnes. trap：受困、困住与诱使 【教材语境】教材用 be trapped in 描写动物或人被困在危险环境中。 【搭配与易错】trap vt./n.；be trapped in 被困在；trap sb into doing sth 诱使某人做某事。trapped是规则双写形式。 【迁移例句】Discarded fishing line can trap seabirds and prevent them from feeding. 【即时小练】Rescuers freed two birds ______ (trap) in fishing line. explode：爆炸与数量激增 【教材语境】教材把 rabbit numbers exploded 用作“数量激增”，而非真实爆炸。 【搭配与易错】explode vi.；explosion n.；an explosion in numbers 数量激增；explode with anger / into laughter 表示情绪突然爆发。 【迁移例句】Once predators disappeared, the rabbit population exploded and vegetation suffered. 【即时小练】Without natural enemies, the population ______ (explode), causing an ecological crisis. collapse：倒塌、崩溃与生态失衡 【教材语境】教材用该词描述斜坡或生态系统因长期破坏而突然失去支撑。 【搭配与易错】collapse vi./n.；a slope / system collapses；collapse into a chair。fall强调落下，collapse强调结构或系统整体失去支撑。 【迁移例句】If plant roots disappear, the bank may collapse after heavy rain. 【即时小练】The damaged bank ______ after the storm, but the team did not let the project collapse. substantial：数量大、程度显著 【教材语境】教材用 a substantial number of 强调保护行动涉及的数量可观。 【搭配与易错】substantial adj. 可表示“大量的、重大的、结实的”；a substantial number of + 复数名词。近义词significant侧重重要或统计意义。 【迁移例句】The reserve made substantial progress, but complete recovery still required time. 【即时小练】A ______ number of volunteers provided ______ support. (substance) intervention：介入与干预 【教材语境】两篇语篇都提醒读者：human intervention既可能造成破坏，也可能修复生态。 【搭配与易错】intervention n.；intervene vi.；intervene in a crisis。interfere常带“妨碍、不当干涉”意味，语气更负面。 【迁移例句】Good intervention begins with evidence and includes follow-up monitoring. 【即时小练】The ecologist argued that people should ______ only after careful observation. (intervention) owe：归因、欠与责任 【教材语境】教材用 owe...to...把生态恢复归因于长期、系统的保护行动。 【搭配与易错】owe A to B 把A归因于B；owe sb sth 欠某人某物；owe it to sb that... 多亏某人……；owing to 因为。 【迁移例句】We owe the wetland's recovery to residents who monitored it for years. 【即时小练】We owe the recovery ______ local residents, and we owe it to them ______ keep monitoring. comparison：比较与对照证据 【教材语境】WHY SHENNONGJIA? 使用数据、例子和比较，使讲座理由更有说服力。 【搭配与易错】make/draw a comparison between；by/in comparison with；compare A with B（比较异同）；compare A to B（比作）。 【迁移例句】A comparison between old and new photographs made the recovery visible. 【即时小练】The report made a ______ between two restoration methods. (compare) apparently：表面看来与证据限度 【教材语境】教材用 apparently 表示“根据现有迹象看来”，保留判断余地。 【搭配与易错】apparently adv.；apparent adj.；It is apparent that...。obviously语气更强，表示“显然”；apparently常暗示信息来自观察或转述。 【迁移例句】The lake is apparently clean, but chemical tests reveal excess nutrients. 【即时小练】The lake is ______ clean, but tests still show excess nutrients. (apparent) secure：安全的、获得与巩固 【教材语境】教材把 secure home 与物种能够长期生存的稳定栖息地联系起来。 【搭配与易错】secure adj./vt.；a secure habitat；feel secure；secure funding / support；security n.。safe强调免受眼前危险，secure更强调稳定、可靠。 【迁移例句】Native plants secure the soil and provide a secure home for insects. 【即时小练】The project aims to provide a ______ habitat and improve water ______. (secure) 知识点2：话题表达与语篇迁移 生态变化与保护表达链 表达功能 核心表达 迁移句型 描述失衡 upset the ecological balance; alien species; out of control Introducing one species may upset the ecological balance and trigger unexpected change. 呈现后果 soil erosion; habitat loss; on the decrease; in consequence Vegetation was damaged; in consequence, nesting areas became less secure. 解释联系 food web; coexist with; depend on; contribute to Each species contributes to a network on which the whole ecosystem depends. 说明行动 remove a threat; monitor change; restore a habitat; once and for all A lasting solution must remove the threat and monitor the system as a whole. 提供证据 according to data; for example; by comparison By comparison with earlier photographs, the recovery is substantial. 升华主题 in harmony with nature; a shared responsibility Conservation works best when people live in harmony with nature and accept shared responsibility. 【运用原则】先写清“变化—原因—后果—行动—证据”，再选择表达；不要把主题词孤立堆砌。 【迁移训练】围绕“Why must conservation be evidence-based?”写3句话：提出观点、给出例子、形成结论。 ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 知识点3：形式宾语it与讲座稿写作 形式宾语it：观察—比较—归纳—判断—运用 【观察】No visitors would think it surprising that the island is a UNESCO World Heritage Site. 【观察】Experts felt it necessary to come up with a plan. 【发现】两句均由it占据宾语位置；真正宾语分别是that从句和to do不定式。 比较维度 形式宾语it 指代性it / 形式主语it 位置与功能 位于谓语后，先占宾语位置；后置真正宾语。 指代性it有明确所指；形式主语it位于句首。 基本结构 V + it + adj./n. + to do / that... It + be + adj. + to do / that... 常见动词 find, think, feel, consider, make, believe 指代性it可跟普通及物动词；形式主语常跟be。 固定结构 owe it to sb that...; take it for granted that...; see to it that... like/hate/appreciate it when/if...中的it也先占宾语位置。 【判断流程】①谓语后是否需要宾语 → ②it后是否有宾补 → ③句尾是否出现to do/that从句 → ④能否把真正宾语前移。 【高频错误】漏写it；把it与真正宾语同时删掉；在make it possible后误用doing；把所有it都解释为“它”。 即时训练 1. We find ______ difficult to predict every consequence of an intervention. 2. New technology makes it possible ______ (monitor) animals without disturbing them. 3. I would appreciate ______ if you could join the wetland survey. 4. Do not take it for granted ______ a green landscape is already healthy. 5. 改错：The team considered was necessary to collect more evidence. _______________________________________________________________________________________ 6. 合并：We believe this. Long-term monitoring can prevent small risks from growing. ______________________________________________________________________________________ 单元写作：Drafting a lecture 讲座环节 内容任务 语言支架 问候与主题 问候听众；提出地点或问题。 Good morning... Today I would like to explain why... 理由与证据 用数据、例子或比较说明价值。 According to... / For example... / By comparison... 行动与意义 说明保护措施及人与自然关系。 We consider it essential to... / This makes it possible for... 总结与问答 回扣观点；提出倡议；结束。 All of this explains why... Thank you. Any questions? 【写作提纲】Topic/Problem: ______　Reason/Evidence: ______　Action: ______　Call: ______ 【自检】□80—100词　□至少2处形式宾语it　□含数据/例子/比较　□讲座开头与结尾完整 【课堂迁移】用50—60词比较Macquarie Island与Shennongjia的保护路径，并至少使用1处形式宾语it。 ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ （建议用时：45分钟　满分：60分　共34题） 一、语境词汇（每题1分，共8分） 1. After protective fencing, the deer population began to ______ steadily rather than rise. (decrease) 2. The young seal was ______ between rocks by the rising tide. (trap) 3. With food abundant and no predators, rabbit numbers ______ within a few years. (explode) 4. Heavy rain caused part of the damaged slope to ______. (collapse) 5. The reserve has made ______ progress in restoring native vegetation. (substance) 6. Early human ______ upset the island's ecological balance. (intervene) 7. The recovery is largely ______ to years of patient monitoring. (owe) 8. A ______ between old and new photographs reveals how much the habitat has changed. (compare) 二、语法与句式迁移（每题2分，共12分） 9. Experts found ______ necessary to study the whole food web before acting. 10. The new sensors make it easier for scientists ______ (monitor) rare animals. 11. We owe it to local volunteers ______ the bee population has remained secure. 12. Do not take it for granted ______ every intervention will produce the intended result. 13. 改写：The team believed that restoring the wetland was possible.（用形式宾语it） ________________________________________________________________________________ 14. 翻译：我们认为每次行动后持续监测生态系统十分重要。（consider it...） ________________________________________________________________________________ 三、阅读理解（每题2.5分，共10分） When “No Pests” Is Only the Beginning In 2014, Macquarie Island was declared free of rabbits, rats and mice after an ambitious eradication programme. For decades, these introduced mammals had eaten native plants, damaged nesting areas and changed relationships across the food web. Removing them was a major success, but scientists did not treat the announcement as the end of the story. Ten years later, researchers returned to examine what recovery actually looked like. The most obvious change was green: tall grasses and other native plants had spread across places that had once been closely grazed. Old photographs made the contrast dramatic. Yet the team also looked beyond attractive scenery. Recovering vegetation can provide shelter, hold soil in place and create conditions in which insects and seabirds can thrive. A change in one part of the system may therefore support several others. The researchers compared new observations with a baseline collected before and during the eradication work. They studied fixed vegetation plots, repeated photographs and records of animal activity. Such evidence matters because species do not all respond at the same speed. Some plants return quickly, while slower-growing communities may need many years. Animals may also wait until suitable food and nesting cover are secure. A single visit could easily miss these different timelines. Success has brought another responsibility: prevention. Ships, equipment and visitors can accidentally carry seeds, insects or disease to a remote island. Careful checks may seem less exciting than a large rescue operation, but they reduce the chance that the same kind of damage will begin again. Long-term monitoring also helps managers notice an unexpected change before it grows out of control. Macquarie Island shows that restoration is not a rewind button. People cannot simply remove a threat and expect every relationship to return immediately. A better measure of success is whether the ecosystem is rebuilding its connections and becoming able to face future pressure. That requires patience, evidence and the willingness to keep learning after the headlines have faded. 15. What did the researchers' return visit mainly reveal? A. The island's landscape had remained almost unchanged. B. Native vegetation had visibly recovered in many places. C. Visitors had become the island's greatest attraction. D. Long-term monitoring was no longer necessary. 16. What does the word "baseline" in paragraph 3 most probably mean? A. A starting set of measurements used for later comparison. B. A legal boundary around a protected area. C. A fence that prevents animals from entering. D. A final score given to a conservation project. 17. What can be inferred from the passage? A. A restored ecosystem never needs further human attention. B. Removing pests guarantees that all species recover together. C. Conservation must continue after the main action has succeeded. D. Attractive scenery is sufficient evidence of full recovery. 18. How is the passage mainly developed? A. By listing instructions for tourists in time order. B. By revisiting a success and drawing a wider lesson from it. C. By comparing the climates of two distant islands. D. By arguing that eradication programmes should be stopped. 四、完形填空（每题1分，共15分） A Small Wetland, A Long Lesson When students at Greenbank School began restoring a small wetland, they 19 ______ the job would be simple: remove rubbish and make the water look clean. Their biology teacher asked them to wait. A wetland, she explained, is not a garden whose success can be judged 20 ______ by appearance. Healthy water must support plants, insects and birds, not merely please the eye. First, the team mapped how water moved through the area. They measured sunlight, water depth and oxygen for two weeks before changing anything. Rather than treating the algae as the problem itself, they looked for the 21 ______ of the extra nutrients. Rainwater 22 ______ fertilizer from nearby lawns entered the pond through a drain. The students placed signs beside the drain and persuaded the school to 23 ______ fertilizer use. They also left part of the bank unmown, 24 ______ native plants to return. Progress was 25 ______ than expected. After one storm, the water turned brown, and several students called the plan a 26 ______ . 27 ______ , tests showed that oxygen levels were improving. The muddy colour 28 ______ from freshly exposed soil, not from a collapse of the ecosystem. Within weeks, plant roots 29 ______ the bank; insects appeared, and birds 30 ______ . The return of these visitors suggested that food and shelter were rebuilding together. Most importantly, the team changed how it measured success. 31 ______ asking whether the pond looked perfect, students recorded oxygen levels, plant variety and visits by birds. This made it 32 ______ to notice small improvements and respond to new 33 ______ . The project taught them that conservation is not a single dramatic act. It is a process of understanding connections, testing decisions and correcting course before a small problem grows out of control. 19. A. assumed B. denied C. forgot D. proved 20. A. only B. seldom C. already D. nearly 21. A. source B. size C. colour D. cost 22. A. carrying B. refusing C. comparing D. securing 23. A. reduce B. record C. trap D. explode 24. A. allowing B. warning C. forcing D. expecting 25. A. slower B. safer C. stranger D. louder 26. A. failure B. comparison C. departure D. greeting 27. A. Yet B. Therefore C. Besides D. Similarly 28. A. came B. prevented C. borrowed D. owed 29. A. secured B. dissolved C. collapsed D. multiplied 30. A. followed B. escaped C. apologised D. hesitated 31. A. Instead of B. Owing to C. Apart from D. In return for 32. A. possible B. rare C. mysterious D. rough 33. A. risks B. lectures C. sessions D. criteria 五、微写作（15分） 34. 假定你是校环保社团代表，请为校园“世界环境日”活动写一篇80—100词英文微型讲座稿，介绍一个脆弱生态系统面临的问题、保护理由、具体行动和结尾倡议；至少使用2处形式宾语it，并至少使用一项数据、例子或对比作为证据。 ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 6 原创精品资源学科网独家享有版权，侵权必究！ 1 学科网（北京）股份有限公司 $