IELTS Reading: Biến Đổi Khí Hậu Và Đại Dương – Đề Thi Mẫu Có Đáp Án Chi Tiết

Mở Bài

Chủ đề biến đổi khí hậu và tác động của nó đến đại dương thế giới là một trong những chủ đề xuất hiện thường xuyên nhất trong các đề thi IELTS Reading thực tế. Từ Cambridge IELTS 10 đến các đề thi gần đây nhất, các bài đọc về môi trường biển, sự ấm lên của đại dương và hệ sinh thái biển luôn chiếm tỷ lệ đáng kể. Điều này phản ánh tầm quan trọng toàn cầu của vấn đề và yêu cầu người học IELTS phải nắm vững cả nội dung chuyên môn lẫn kỹ năng đọc hiểu học thuật.

Trong bài viết này, bạn sẽ được thực hành với một đề thi IELTS Reading hoàn chỉnh gồm 3 passages với độ khó tăng dần từ Easy đến Hard, bao gồm tất cả 40 câu hỏi như trong kỳ thi thật. Mỗi passage được thiết kế dựa trên format chuẩn Cambridge, với các dạng câu hỏi đa dạng như Multiple Choice, True/False/Not Given, Yes/No/Not Given, Matching Headings, và Summary Completion. Bên cạnh đề thi, bạn sẽ nhận được đáp án chi tiết kèm giải thích cụ thể, phân tích kỹ thuật paraphrase, và bộ từ vựng quan trọng được trích xuất từng passage.

Đề thi này phù hợp cho học viên từ band 5.0 trở lên, đặc biệt hữu ích cho những bạn đang hướng đến band 6.5-7.5 và cần làm quen với các chủ đề môi trường học thuật.

1. Hướng Dẫn Làm Bài IELTS Reading

Tổng Quan Về IELTS Reading Test

IELTS Reading Test kéo dài 60 phút với 3 passages và tổng cộng 40 câu hỏi. Đây là bài thi không có thời gian chuyển đáp án riêng, vì vậy bạn phải quản lý thời gian một cách khoa học.

Phân bổ thời gian khuyến nghị:

• Passage 1 (Easy): 15-17 phút – Đây là passage dễ nhất, bạn cần tận dụng để ghi điểm tối đa
• Passage 2 (Medium): 18-20 phút – Độ khó trung bình, yêu cầu kỹ năng paraphrase tốt
• Passage 3 (Hard): 23-25 phút – Passage khó nhất, cần thời gian phân tích và suy luận

Lưu ý quan trọng: Luôn dành 2-3 phút cuối để kiểm tra và chuyển đáp án vào Answer Sheet một cách cẩn thận.

Các Dạng Câu Hỏi Trong Đề Này

Đề thi mẫu này bao gồm 7 dạng câu hỏi phổ biến nhất trong IELTS Reading:

1. Multiple Choice – Câu hỏi trắc nghiệm với 3-4 lựa chọn
2. True/False/Not Given – Xác định thông tin đúng, sai hay không được đề cập
3. Yes/No/Not Given – Xác định quan điểm của tác giả
4. Matching Headings – Nối tiêu đề với đoạn văn
5. Sentence Completion – Hoàn thành câu với từ trong bài
6. Summary Completion – Điền từ vào tóm tắt
7. Short-answer Questions – Trả lời câu hỏi ngắn

Mỗi dạng câu hỏi yêu cầu kỹ năng khác nhau: scanning cho thông tin cụ thể, skimming cho ý chính, và close reading cho phân tích chi tiết.

2. IELTS Reading Practice Test

PASSAGE 1 – The Ocean’s Changing Temperature

Độ khó: Easy (Band 5.0-6.5)

Thời gian đề xuất: 15-17 phút

The world’s oceans are experiencing unprecedented changes in temperature, and these shifts are having profound effects on marine life and global weather patterns. Scientists have been monitoring ocean temperatures for decades, and the data reveals a clear and concerning trend: our oceans are getting warmer at an accelerating rate.

Surface waters in most parts of the world have increased in temperature by approximately 0.13 degrees Celsius per decade over the past century. While this might seem like a small number, it represents an enormous amount of heat energy being absorbed by the oceans. In fact, the oceans have absorbed more than 90% of the excess heat trapped by greenhouse gases in Earth’s atmosphere. This heat absorption has helped to slow the rate of atmospheric warming, but it comes at a significant cost to marine ecosystems.

The warming of ocean waters affects marine life in multiple ways. Many fish species are highly sensitive to temperature changes and are now migrating toward cooler waters near the poles. This migration pattern disrupts traditional fishing grounds and affects the livelihoods of millions of people who depend on fishing. Coral reefs, which are among the most biodiverse ecosystems on the planet, are particularly vulnerable. When water temperatures rise just 1-2 degrees above normal summer maximums, corals experience bleaching events. During bleaching, corals expel the symbiotic algae living in their tissues, turning white and often dying if conditions don’t improve quickly.

Ocean circulation patterns are also being altered by warming waters. The thermohaline circulation, sometimes called the “global conveyor belt,” is a system of ocean currents that distributes heat around the planet. This circulation is driven by differences in water temperature and salinity. As polar ice melts due to warming, it adds fresh water to the oceans, which can disrupt these circulation patterns. Scientists worry that significant changes to ocean circulation could lead to dramatic shifts in regional climates, particularly in Europe, which is kept relatively warm by the Gulf Stream.

The relationship between ocean temperature and weather is complex but crucial. Warmer oceans provide more energy for storms, leading to more intense hurricanes and typhoons. The water vapor evaporating from warm ocean surfaces becomes fuel for these powerful weather systems. Records show that the number of Category 4 and 5 hurricanes has increased in recent decades, and many scientists link this trend to rising ocean temperatures.

Coastal communities around the world are already experiencing the effects of warmer oceans. Thermal expansion – the tendency of water to expand as it warms – is one of the main contributors to sea-level rise. As ocean water warms, it takes up more space, causing sea levels to increase even before accounting for melting ice sheets and glaciers. This expansion has contributed to approximately one-third of the observed sea-level rise over the past century.

Some regions are warming faster than others. The Arctic Ocean, for example, is warming at roughly twice the global average rate. This phenomenon, known as Arctic amplification, creates a feedback loop: as ice melts, it exposes darker ocean water that absorbs more sunlight than reflective ice, leading to even more warming. The consequences extend far beyond the Arctic itself, influencing weather patterns across the Northern Hemisphere.

Despite these challenges, there is hope. Understanding ocean temperature changes helps scientists make better predictions about future climate scenarios. International cooperation on reducing greenhouse gas emissions could slow the rate of ocean warming. Additionally, some marine species show remarkable adaptability, and conservation efforts focused on protecting critical habitats can help ecosystems become more resilient to temperature changes. However, the window for effective action is narrowing, and the decisions made in the coming decades will determine the future health of our oceans and the billions of people who depend on them.

Hình ảnh minh họa đại dương nóng lên do biến đổi khí hậu với nhiệt độ tăng cao ảnh hưởng hệ sinh thái biển

Questions 1-13

Questions 1-5: Multiple Choice

Choose the correct letter, A, B, C or D.

1. According to the passage, surface ocean temperatures have risen by

• A. 0.13 degrees per year
• B. 0.13 degrees per decade
• C. 1.3 degrees per century
• D. 13 degrees per century

2. What percentage of excess atmospheric heat have the oceans absorbed?

• A. More than 50%
• B. Exactly 75%
• C. More than 90%
• D. 100%

3. Coral bleaching occurs when

• A. water becomes too salty
• B. temperatures rise 1-2 degrees above normal
• C. fish migrate to new areas
• D. ocean currents change direction

4. The thermohaline circulation is driven by differences in

• A. temperature and salinity
• B. wave height and depth
• C. wind speed and direction
• D. sunlight and darkness

5. Thermal expansion contributes to sea-level rise by approximately

• A. one-quarter
• B. one-third
• C. one-half
• D. two-thirds

Questions 6-9: True/False/Not Given

Do the following statements agree with the information given in the passage?

Write:

• TRUE if the statement agrees with the information
• FALSE if the statement contradicts the information
• NOT GIVEN if there is no information on this

6. Fish species moving toward polar regions are helping fishing communities earn more income.

7. The Gulf Stream helps keep Europe’s climate relatively warm.

8. The number of powerful hurricanes has decreased in recent decades.

9. The Arctic Ocean is warming at approximately twice the global average rate.

Questions 10-13: Sentence Completion

Complete the sentences below.

Choose NO MORE THAN THREE WORDS from the passage for each answer.

10. Corals expel _____ from their tissues during bleaching events.

11. Warmer oceans provide more _____ for storms to develop.

12. Arctic amplification creates a _____ that leads to more warming.

13. Some marine species demonstrate _____ to changing conditions.

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PASSAGE 2 – Ocean Acidification: The Other CO2 Problem

Độ khó: Medium (Band 6.0-7.5)

Thời gian đề xuất: 18-20 phút

While much attention has been focused on the atmospheric accumulation of carbon dioxide and its role in global warming, a parallel crisis is unfolding beneath the ocean’s surface. The world’s oceans are becoming more acidic at a rate unprecedented in at least 300 million years, and this chemical transformation poses a fundamental threat to marine ecosystems. Scientists refer to this phenomenon as “the other CO2 problem,” and its consequences could be as catastrophic as those of atmospheric warming.

The chemistry behind ocean acidification is relatively straightforward. When carbon dioxide from the atmosphere dissolves in seawater, it forms carbonic acid, which releases hydrogen ions. These hydrogen ions bond with carbonate ions in the water, reducing the availability of carbonate for marine organisms. This process has caused ocean pH levels to drop by approximately 0.1 units since the Industrial Revolution – a change that represents a 30% increase in acidity. While the ocean remains slightly alkaline overall, the trend is clearly toward greater acidity, and the rate of change is what concerns scientists most.

The implications of this chemical shift are far-reaching. Many marine organisms, including corals, mollusks, and certain plankton species, build their shells and skeletons from calcium carbonate. As carbonate ions become less available, these organisms face increasing difficulty in forming and maintaining their structures. Laboratory experiments have shown that shellfish larvae exposed to more acidic conditions produce thinner, weaker shells and experience higher mortality rates. Some species of pteropods – tiny swimming snails that form a crucial part of the ocean food web – already show signs of shell dissolution in waters off the Pacific Northwest.

Coral reefs, already stressed by warming waters, face an additional challenge from acidification. The process of calcification, through which corals build their limestone skeletons, becomes more difficult in acidic conditions. Research conducted on the Great Barrier Reef has revealed that calcification rates have declined by 14% since 1990. If current trends continue, many coral species may be unable to build their structures faster than erosion breaks them down, leading to the gradual disintegration of reef systems that support approximately 25% of all marine species.

The effects extend beyond organisms with shells. Ocean acidification can affect the sensory systems of fish, particularly their ability to detect predators and navigate using chemical cues. Studies on clownfish larvae have demonstrated that exposure to elevated CO2 levels impairs their sense of smell, making them more vulnerable to predation. This could have cascading effects throughout marine food webs, as changes in predator-prey relationships ripple through ecosystems.

Regional variations in ocean acidification add complexity to the problem. Upwelling zones, where deep, CO2-rich waters rise to the surface, experience particularly high acidity levels. The Southern Ocean around Antarctica is acidifying more rapidly than other regions due to its cold waters, which absorb CO2 more readily. These variations mean that some marine communities will face acute challenges before others, potentially leading to abrupt ecosystem changes in vulnerable areas.

San hô bị ảnh hưởng bởi quá trình axit hóa đại dương với cấu trúc vôi bị suy yếu do pH nước biển giảm

The economic implications are substantial. The global shellfish industry, valued at billions of dollars annually, is particularly vulnerable. Oyster hatcheries in Oregon and Washington have already experienced massive die-offs linked to acidified water. These commercial operations have had to adapt by monitoring water chemistry carefully and timing their production cycles to avoid periods when upwelling brings particularly acidic water to the surface. The costs of such adaptations, along with potential production losses, could transform the industry.

Perhaps most concerning is the pace of change. During previous periods of ocean acidification in Earth’s history, the process unfolded over thousands or millions of years, allowing marine life time to adapt through evolutionary processes. The current rate of acidification is occurring over decades, leaving little time for adaptation. Paleontological evidence from past acidification events suggests that recovery of marine ecosystems can take hundreds of thousands of years after conditions stabilize.

Despite this sobering picture, research into ocean acidification is advancing rapidly, and some mitigation strategies are being explored. Reducing CO2 emissions remains the most crucial step. Some scientists are investigating whether adding alkaline materials to seawater could counteract acidification locally, though the feasibility and ecological impacts of such geoengineering approaches remain uncertain. Others focus on identifying naturally resilient species and understanding the mechanisms that allow some organisms to thrive in more acidic conditions.

International scientific collaboration has intensified, with research programs monitoring acidification globally and developing more sophisticated models to predict future changes. Understanding regional differences and identifying refugia – areas where conditions may remain more favorable – could help prioritize conservation efforts. Meanwhile, some marine organisms have shown surprising physiological plasticity, suggesting that adaptation may be possible for certain species if emission reduction efforts succeed in slowing the rate of change.

The challenge of ocean acidification underscores the interconnected nature of Earth’s systems. Actions taken on land, primarily the burning of fossil fuels, have consequences that ripple through ocean chemistry, affecting life forms from microscopic plankton to the humans who depend on healthy marine ecosystems. Addressing this challenge requires not only scientific understanding but also political will and coordinated global action on an unprecedented scale.

Questions 14-26

Questions 14-18: Yes/No/Not Given

Do the following statements agree with the claims of the writer in the passage?

Write:

• YES if the statement agrees with the claims of the writer
• NO if the statement contradicts the claims of the writer
• NOT GIVEN if it is impossible to say what the writer thinks about this

14. Ocean acidification is receiving more public attention than atmospheric carbon dioxide accumulation.

15. The rate of ocean acidification is faster than anything seen in the last 300 million years.

16. The ocean has already become fully acidic rather than alkaline.

17. Pteropods play an important role in ocean food webs.

18. All fish species are equally affected by ocean acidification.

Questions 19-22: Matching Headings

The passage has nine paragraphs (excluding the first paragraph). Choose the correct heading for paragraphs B, D, F, and H from the list of headings below.

List of Headings:

• i. Economic consequences for marine industries
• ii. The basic chemistry of carbon absorption
• iii. Variations across different ocean regions
• iv. Effects on fish behavior and senses
• v. Potential solutions and ongoing research
• vi. Threats to shell-building organisms
• vii. Historical comparison of acidification events
• viii. Impact on coral reef structures
• ix. The role of ocean currents

19. Paragraph B (starts with “The chemistry behind…”)

20. Paragraph D (starts with “Coral reefs, already stressed…”)

21. Paragraph F (starts with “Regional variations…”)

22. Paragraph H (starts with “Perhaps most concerning…”)

Questions 23-26: Summary Completion

Complete the summary below.

Choose NO MORE THAN TWO WORDS from the passage for each answer.

Ocean acidification occurs when CO2 dissolves in seawater and forms 23 . This reduces the availability of carbonate ions that marine creatures need to build shells. The ocean’s pH has decreased by 0.1 units since the 24 , representing a 30% increase in acidity. Organisms such as 25 are already showing signs of shell dissolution in some areas. The shellfish industry has been forced to monitor 26 carefully to avoid the most acidic conditions.

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PASSAGE 3 – Marine Ecosystem Transformations and Cascading Effects

Độ khó: Hard (Band 7.0-9.0)

Thời gian đề xuất: 23-25 phút

The synergistic impacts of ocean warming and acidification are precipitating comprehensive transformations in marine ecosystems that extend far beyond the direct physiological effects on individual species. These changes manifest through complex ecological cascades that restructure food webs, alter biogeochemical cycles, and fundamentally reshape the spatial distribution of marine biodiversity. Understanding these systemic shifts requires an integrated perspective that considers not merely isolated environmental stressors but rather their cumulative and interactive effects on intricate biological networks.

Contemporary research has revealed that ocean warming is driving poleward migrations at an average rate of 72 kilometers per decade for numerous marine species, a velocity that substantially exceeds the migration rates observed in terrestrial ecosystems. This redistributive phenomenon is not occurring uniformly across taxonomic groups; different species respond according to their thermal tolerances, reproductive strategies, and ecological relationships. The result is the formation of “no-analog communities” – assemblages of species that have no historical precedent and whose ecological dynamics are fundamentally unpredictable. These novel ecosystems challenge traditional conservation approaches predicated on maintaining historical baselines and raise profound questions about the very concept of ecosystem restoration in a rapidly changing ocean.

The trophic cascades initiated by these redistributions can be particularly disruptive. Consider the case of the Northwest Atlantic, where warming waters have facilitated the northward expansion of subtropical predators while simultaneously reducing the abundance of cold-adapted prey species. This has resulted in dietary shifts for commercially important fish stocks, alterations in energy transfer efficiency between trophic levels, and changes in the nutritional quality of prey available to higher-order consumers. In some instances, the arrival of new predators has triggered trophic downgrading, whereby top predators exert disproportionate control over ecosystem structure, leading to the suppression of intermediate consumer species and sometimes resulting in the proliferation of their prey.

Oxygen depletion, or hypoxia, represents another critical consequence of ocean warming that acts synergistically with other stressors. Warmer water holds less dissolved oxygen, while simultaneously, higher temperatures increase the metabolic demands of marine organisms, creating a physiological squeeze. Furthermore, warming enhances stratification – the formation of distinct water layers that resist mixing – which reduces the transfer of oxygen from surface waters to deeper layers. The expansion of oxygen minimum zones has been documented across multiple ocean basins, creating physiological barriers that compress the viable habitat for numerous species into progressively narrower vertical ranges. This “habitat compression” increases vulnerability to both fishing pressure and predation while reducing the environmental refugia available during extreme conditions.

The implications for primary productivity – the foundation of marine food webs – are complex and regionally variable. While some models predict that warming might enhance productivity in certain high-latitude regions through extended growing seasons and reduced ice cover, evidence suggests that nutrient limitations may constrain such increases. Ocean stratification impedes the vertical mixing that brings nutrients from deeper waters to the euphotic zone where phytoplankton conduct photosynthesis. Consequently, while some regions may experience transient productivity gains, many subtropical and tropical regions are expected to face long-term productivity declines. These shifts have ramifications that extend throughout food webs, ultimately affecting fisheries yields and the provisioning services that oceans provide to human populations.

Thực vật phiêu lưu biển đóng vai trò quan trọng trong chuỗi thức ăn đại dương bị ảnh hưởng bởi biến đổi nhiệt độ

The phenomenon of marine heatwaves – prolonged periods of anomalously warm ocean temperatures – has emerged as a particularly pernicious manifestation of climate change. These events, which have increased in frequency and intensity, can cause acute ecological disruptions that persist long after temperatures normalize. The 2011 heatwave off Western Australia resulted in the loss of over 90% of a kelp forest that supported a diverse community of species, with the ecosystem state shifting to a turf algae dominated system. Similarly, marine heatwaves in the Northeast Pacific between 2013 and 2016, colloquially termed “the Blob,” triggered unprecedented harmful algal blooms, seabird die-offs, and the redistribution of commercially important fish species, generating profound consequences for both ecosystems and fishing-dependent communities.

Evolutionary responses to rapidly changing ocean conditions represent a crucial area of inquiry. While some species demonstrate phenotypic plasticity – the capacity to adjust physiological or behavioral traits within a single generation – the extent to which genetic adaptation can occur at rates commensurate with environmental change remains uncertain. Research on marine copepods and other organisms with short generation times suggests that adaptive evolution may be possible for some taxa. However, many long-lived species with extended reproductive cycles, including numerous commercially important fish and many marine mammals, may lack the evolutionary velocity necessary to keep pace with changing conditions. The selective pressures imposed by multiple simultaneous stressors may also result in maladaptive trait combinations or genetic bottlenecks that reduce population viability.

From a biogeochemical perspective, changes in ocean ecosystems have implications that extend to global carbon cycling. The ocean’s biological carbon pump – whereby carbon fixed through photosynthesis in surface waters is transported to the deep ocean through sinking particles and migrating organisms – plays a crucial role in regulating atmospheric CO2 concentrations. Alterations in phytoplankton community composition, changes in the efficiency of carbon export from surface to deep waters, and modifications to the abundance and distribution of calcifying organisms all have the potential to affect the ocean’s capacity to absorb and sequester carbon. While uncertainties remain regarding the magnitude and directionality of these effects, the potential for positive feedback loops – wherein ocean changes reduce carbon uptake, leading to accelerated atmospheric warming – represents a significant concern.

The challenge of managing marine resources amid these transformative changes has necessitated a shift toward more adaptive and integrated approaches. Traditional fisheries management, which often relied on assumptions of environmental stationarity and species distributions, must now incorporate considerations of dynamic baselines and shifting ecological relationships. Marine spatial planning increasingly recognizes the need for climate-adaptive designs that account for distributional shifts and the potential for ecosystem reorganization. The concept of resilience-based management – focusing on maintaining ecosystem functions and the capacity to absorb disturbances rather than preserving specific species compositions – has gained prominence as a pragmatic framework for navigating ecological uncertainty.

Perhaps most fundamentally, the comprehensive restructuring of marine ecosystems underscores the profound interconnectedness between ocean health and human well-being. Oceans provide essential services including food security, climate regulation, coastal protection, and cultural values to billions of people. The cascading effects of climate change on marine ecosystems thus represent not merely an environmental challenge but a multifaceted crisis with humanitarian dimensions. Addressing this crisis requires transdisciplinary collaboration that integrates ecological science, social science, economics, and policy expertise to develop solutions that are both ecologically sound and socially equitable. The decisions made in the coming decades will determine whether humanity can forge a sustainable relationship with the marine realm or whether we will witness the irreversible degradation of one of Earth’s most vital life-support systems.

Questions 27-40

Questions 27-31: Multiple Choice

Choose the correct letter, A, B, C or D.

27. According to the passage, “no-analog communities” are

• A. communities that have existed in the past
• B. species assemblages without historical precedent
• C. communities that resist climate change
• D. groups of species from the same taxonomic family

28. The passage suggests that ocean stratification

• A. increases oxygen levels in deep water
• B. improves nutrient distribution
• C. reduces vertical mixing of water layers
• D. enhances phytoplankton growth throughout the ocean

29. “Habitat compression” refers to

• A. the expansion of available living space
• B. the narrowing of viable habitat ranges for marine species
• C. the compression of water due to pressure
• D. the reduction in ocean depth

30. The 2011 marine heatwave off Western Australia resulted in

• A. increased kelp forest coverage
• B. the recovery of diverse marine species
• C. a shift to a turf algae dominated ecosystem
• D. improved fishing conditions

31. According to the passage, evolutionary adaptation to changing ocean conditions

• A. is occurring equally across all species
• B. is more feasible for short-lived species with rapid reproduction
• C. is impossible for any marine organisms
• D. only affects phytoplankton communities

Questions 32-36: Matching Features

Match the following concepts with their correct descriptions.

Write the correct letter, A-H, next to questions 32-36.

Concepts:

• 32. Trophic cascades
• 33. Phenotypic plasticity
• 34. Biological carbon pump
• 35. Marine spatial planning
• 36. Resilience-based management

Descriptions:

• A. The ability to adjust traits within one generation
• B. The process of carbon transport from surface to deep ocean
• C. Managing ecosystems by preserving specific historical species
• D. Disruptions in food webs caused by species redistributions
• E. Designing marine protected areas to account for climate change
• F. The warming of surface ocean waters
• G. Focusing on maintaining ecosystem functions rather than species composition
• H. The migration of species toward the equator

Questions 37-40: Short-answer Questions

Answer the questions below.

Choose NO MORE THAN THREE WORDS from the passage for each answer.

37. At what average rate (per decade) are many marine species migrating toward the poles?

38. What term describes prolonged periods of unusually warm ocean temperatures?

39. What was the nickname given to marine heatwaves in the Northeast Pacific between 2013-2016?

40. What type of organisms, when their abundance changes, can affect the ocean’s capacity to absorb carbon?

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3. Answer Keys – Đáp Án

PASSAGE 1: Questions 1-13

1. B
2. C
3. B
4. A
5. B
6. FALSE
7. TRUE
8. FALSE
9. TRUE
10. symbiotic algae
11. energy
12. feedback loop
13. remarkable adaptability

PASSAGE 2: Questions 14-26

14. NO
15. YES
16. NO
17. YES
18. NOT GIVEN
19. ii
20. viii
21. iii
22. vii
23. carbonic acid
24. Industrial Revolution
25. pteropods
26. water chemistry

PASSAGE 3: Questions 27-40

27. B
28. C
29. B
30. C
31. B
32. D
33. A
34. B
35. E
36. G
37. 72 kilometers / seventy-two kilometers
38. marine heatwaves
39. the Blob
40. calcifying organisms

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4. Giải Thích Đáp Án Chi Tiết

Passage 1 – Giải Thích

Câu 1: B

• Dạng câu hỏi: Multiple Choice
• Từ khóa: surface ocean temperatures, risen
• Vị trí trong bài: Đoạn 2, dòng 1-2
• Giải thích: Bài viết nêu rõ “Surface waters in most parts of the world have increased in temperature by approximately 0.13 degrees Celsius per decade over the past century.” Đáp án B chính xác là “per decade” (mỗi thập kỷ).

Câu 2: C

• Dạng câu hỏi: Multiple Choice
• Từ khóa: percentage, excess atmospheric heat, absorbed
• Vị trí trong bài: Đoạn 2, dòng 3-4
• Giải thích: Đoạn văn cho biết “the oceans have absorbed more than 90% of the excess heat trapped by greenhouse gases.” Chú ý từ khóa “more than 90%” tương ứng với đáp án C.

Câu 3: B

• Dạng câu hỏi: Multiple Choice
• Từ khóa: Coral bleaching, occurs when
• Vị trí trong bài: Đoạn 3, dòng 5-6
• Giải thích: Bài viết nêu “When water temperatures rise just 1-2 degrees above normal summer maximums, corals experience bleaching events.” Đây là paraphrase của đáp án B.

Câu 6: FALSE

• Dạng câu hỏi: True/False/Not Given
• Từ khóa: Fish species, polar regions, fishing communities, earn more income
• Vị trí trong bài: Đoạn 3, dòng 2-4
• Giải thích: Bài viết nói rằng sự di cư của cá “disrupts traditional fishing grounds and affects the livelihoods of millions of people.” Điều này mâu thuẫn với việc giúp cộng đồng đánh cá kiếm được nhiều thu nhập hơn.

Câu 7: TRUE

• Dạng câu hỏi: True/False/Not Given
• Từ khóa: Gulf Stream, Europe’s climate, warm
• Vị trí trong bài: Đoạn 4, dòng cuối
• Giải thích: Đoạn văn nêu rõ “particularly in Europe, which is kept relatively warm by the Gulf Stream.” Đây là thông tin khớp hoàn toàn với phát biểu.

Câu 10: symbiotic algae

• Dạng câu hỏi: Sentence Completion
• Từ khóa: Corals expel, tissues, bleaching events
• Vị trí trong bài: Đoạn 3, dòng 6-7
• Giải thích: “During bleaching, corals expel the symbiotic algae living in their tissues” – cụm “symbiotic algae” là đáp án chính xác.

Câu 12: feedback loop

• Dạng câu hỏi: Sentence Completion
• Từ khóa: Arctic amplification, creates
• Vị trí trong bài: Đoạn 7, dòng 2-3
• Giải thích: Bài viết nêu “This phenomenon, known as Arctic amplification, creates a feedback loop” – cần chú ý đến cấu trúc câu và từ khóa “creates”.

Học viên đang làm bài thi IELTS Reading với kỹ thuật scanning và skimming để tìm đáp án

Passage 2 – Giải Thích

Câu 14: NO

• Dạng câu hỏi: Yes/No/Not Given
• Từ khóa: Ocean acidification, more public attention, atmospheric carbon dioxide
• Vị trí trong bài: Đoạn 1, câu đầu
• Giải thích: Đoạn mở bài nói “While much attention has been focused on the atmospheric accumulation of carbon dioxide” – từ “while” cho thấy sự tương phản, nghĩa là axit hóa đại dương nhận được ít sự chú ý hơn, không phải nhiều hơn.

Câu 15: YES

• Dạng câu hỏi: Yes/No/Not Given
• Từ khóa: rate, faster, 300 million years
• Vị trí trong bài: Đoạn 1, dòng 2-3
• Giải thích: Bài viết khẳng định “The world’s oceans are becoming more acidic at a rate unprecedented in at least 300 million years” – “unprecedented” có nghĩa là chưa từng có, tức là nhanh nhất.

Câu 16: NO

• Dạng câu hỏi: Yes/No/Not Given
• Từ khóa: ocean, fully acidic, alkaline
• Vị trí trong bài: Đoạn 2, dòng cuối
• Giải thích: Đoạn văn nói rõ “While the ocean remains slightly alkaline overall” – điều này mâu thuẫn trực tiếp với phát biểu rằng đại dương đã trở nên hoàn toàn axit.

Câu 19: ii

• Dạng câu hỏi: Matching Headings
• Từ khóa: chemistry, carbon dioxide, carbonic acid
• Vị trí trong bài: Đoạn B (đoạn thứ hai)
• Giải thích: Đoạn này bắt đầu với “The chemistry behind ocean acidification is relatively straightforward” và giải thích chi tiết về quá trình hóa học khi CO2 hòa tan trong nước biển. Heading “The basic chemistry of carbon absorption” phù hợp nhất.

Câu 20: viii

• Dạng câu hỏi: Matching Headings
• Từ khóa: coral reefs, calcification, limestone skeletons
• Vị trí trong bài: Đoạn D (đoạn thứ tư)
• Giải thích: Toàn bộ đoạn này tập trung vào tác động của axit hóa lên rạn san hô, đặc biệt là quá trình vôi hóa và cấu trúc xương đá vôi. Heading “Impact on coral reef structures” phản ánh chính xác nội dung.

Câu 23: carbonic acid

• Dạng câu hỏi: Summary Completion
• Từ khóa: CO2 dissolves, seawater, forms
• Vị trí trong bài: Đoạn 2, dòng 1-2
• Giải thích: “When carbon dioxide from the atmosphere dissolves in seawater, it forms carbonic acid” – đáp án là “carbonic acid”, cần chú ý viết đúng cả hai từ.

Câu 26: water chemistry

• Dạng câu hỏi: Summary Completion
• Từ khóa: shellfish industry, monitor, carefully
• Vị trí trong bài: Đoạn 7, dòng 3-5
• Giải thích: “These commercial operations have had to adapt by monitoring water chemistry carefully” – cụm “water chemistry” là đáp án chính xác.

Passage 3 – Giải Thích

Câu 27: B

• Dạng câu hỏi: Multiple Choice
• Từ khóa: no-analog communities
• Vị trí trong bài: Đoạn 2, dòng 4-6
• Giải thích: Bài viết định nghĩa rõ ràng: “no-analog communities – assemblages of species that have no historical precedent.” Đây là paraphrase trực tiếp của đáp án B “species assemblages without historical precedent”.

Câu 28: C

• Dạng câu hỏi: Multiple Choice
• Từ khóa: ocean stratification
• Vị trí trong bài: Đoạn 4, dòng 3-5
• Giải thích: Đoạn văn giải thích “warming enhances stratification – the formation of distinct water layers that resist mixing – which reduces the transfer of oxygen from surface waters to deeper layers.” Điều này tương ứng với đáp án C về việc giảm sự trộn lẫn theo chiều dọc.

Câu 30: C

• Dạng câu hỏi: Multiple Choice
• Từ khóa: 2011 marine heatwave, Western Australia
• Vị trí trong bài: Đoạn 6, dòng 3-5
• Giải thích: Bài viết nêu rõ “The 2011 heatwave off Western Australia resulted in the loss of over 90% of a kelp forest… with the ecosystem state shifting to a turf algae dominated system.” Đáp án C chính xác mô tả sự chuyển đổi này.

Câu 32: D

• Dạng câu hỏi: Matching Features
• Từ khóa: Trophic cascades
• Vị trí trong bài: Đoạn 3
• Giải thích: Đoạn 3 mô tả “The trophic cascades initiated by these redistributions can be particularly disruptive” và tiếp tục giải thích về các gián đoạn trong chuỗi thức ăn. Mô tả D “Disruptions in food webs caused by species redistributions” phù hợp chính xác.

Câu 33: A

• Dạng câu hỏi: Matching Features
• Từ khóa: Phenotypic plasticity
• Vị trí trong bài: Đoạn 7, dòng 2-3
• Giải thích: Bài viết định nghĩa rõ ràng: “phenotypic plasticity – the capacity to adjust physiological or behavioral traits within a single generation.” Đây là paraphrase của mô tả A.

Câu 37: 72 kilometers

• Dạng câu hỏi: Short-answer Questions
• Từ khóa: average rate, per decade, migrating toward poles
• Vị trí trong bài: Đoạn 2, dòng 1-2
• Giải thích: “ocean warming is driving poleward migrations at an average rate of 72 kilometers per decade” – đáp án có thể viết là “72 kilometers” hoặc “seventy-two kilometers”.

Câu 39: the Blob

• Dạng câu hỏi: Short-answer Questions
• Từ khóa: nickname, Northeast Pacific, 2013-2016
• Vị trí trong bài: Đoạn 6, dòng 6-7
• Giải thích: “marine heatwaves in the Northeast Pacific between 2013 and 2016, colloquially termed ‘the Blob'” – cần viết chính xác “the Blob” bao gồm cả mạo từ “the”.

Câu 40: calcifying organisms

• Dạng câu hỏi: Short-answer Questions
• Từ khóa: abundance changes, affect, ocean’s capacity, absorb carbon
• Vị trí trong bài: Đoạn 8, dòng 4-6
• Giải thích: Bài viết đề cập “modifications to the abundance and distribution of calcifying organisms all have the potential to affect the ocean’s capacity to absorb and sequester carbon.” Đáp án là “calcifying organisms”.

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5. Từ Vựng Quan Trọng Theo Passage

Passage 1 – Essential Vocabulary

Từ vựng	Loại từ	Phiên âm	Nghĩa tiếng Việt	Ví dụ từ bài	Collocation
unprecedented	adj	/ʌnˈpresɪdentɪd/	chưa từng có, chưa có tiền lệ	unprecedented changes in temperature	unprecedented scale/level/rate
profound	adj	/prəˈfaʊnd/	sâu sắc, to lớn	profound effects on marine life	profound impact/effect/influence
accelerating	adj	/əkˈseləreɪtɪŋ/	đang tăng tốc	at an accelerating rate	accelerating pace/trend/rate
greenhouse gases	n	/ˈɡriːnhaʊs ˌɡæsɪz/	khí nhà kính	trapped by greenhouse gases	emit/reduce greenhouse gases
migration pattern	n	/maɪˈɡreɪʃn ˈpætən/	mô hình di cư	This migration pattern disrupts fishing	follow/track migration patterns
biodiverse	adj	/ˌbaɪəʊdaɪˈvɜːs/	đa dạng sinh học	most biodiverse ecosystems	biodiverse region/area/habitat
bleaching events	n	/ˈbliːtʃɪŋ ɪˈvents/	sự kiện tẩy trắng (san hô)	corals experience bleaching events	coral bleaching events
symbiotic	adj	/ˌsɪmbaɪˈɒtɪk/	cộng sinh	symbiotic algae living in tissues	symbiotic relationship/association
thermohaline circulation	n	/ˌθɜːməʊˈheɪlaɪn ˌsɜːkjʊˈleɪʃn/	tuần hoàn nhiệt muối	The thermohaline circulation is driven	affect/disrupt thermohaline circulation
disrupt	v	/dɪsˈrʌpt/	phá vỡ, gián đoạn	can disrupt these circulation patterns	disrupt patterns/systems/processes
thermal expansion	n	/ˈθɜːməl ɪkˈspænʃn/	sự giãn nở nhiệt	Thermal expansion causes sea-level rise	contribute to thermal expansion
phenomenon	n	/fəˈnɒmɪnən/	hiện tượng	This phenomenon is known as Arctic amplification	natural/observed phenomenon

Passage 2 – Essential Vocabulary

Từ vựng	Loại từ	Phiên âm	Nghĩa tiếng Việt	Ví dụ từ bài	Collocation
atmospheric accumulation	n	/ˌætməsˈferɪk əˌkjuːmjʊˈleɪʃn/	sự tích tụ trong khí quyển	atmospheric accumulation of carbon dioxide	lead to atmospheric accumulation
chemical transformation	n	/ˈkemɪkl ˌtrænsfəˈmeɪʃn/	sự biến đổi hóa học	this chemical transformation poses a threat	undergo chemical transformation
fundamental threat	n	/ˌfʌndəˈmentl θret/	mối đe dọa căn bản	poses a fundamental threat	represent/pose a fundamental threat
catastrophic	adj	/ˌkætəˈstrɒfɪk/	thảm khốc	could be as catastrophic as	catastrophic consequences/effects
carbonic acid	n	/kɑːˌbɒnɪk ˈæsɪd/	axit cacbonic	it forms carbonic acid	produce/form carbonic acid
hydrogen ions	n	/ˈhaɪdrədʒən ˈaɪɒnz/	ion hydro	releases hydrogen ions	release/produce hydrogen ions
alkaline	adj	/ˈælkəlaɪn/	kiềm	the ocean remains slightly alkaline	alkaline conditions/environment
mortality rates	n	/mɔːˈtæləti reɪts/	tỷ lệ tử vong	experience higher mortality rates	increase/reduce mortality rates
calcification	n	/ˌkælsɪfɪˈkeɪʃn/	quá trình vôi hóa	The process of calcification becomes difficult	coral/reef calcification
limestone skeletons	n	/ˈlaɪmstəʊn ˈskelɪtnz/	bộ xương đá vôi	corals build their limestone skeletons	form limestone skeletons
gradual disintegration	n	/ˈɡrædʒuəl dɪsˌɪntɪˈɡreɪʃn/	sự tan rã dần dần	leading to the gradual disintegration	gradual disintegration of structures
cascading effects	n	/kæsˈkeɪdɪŋ ɪˈfekts/	hiệu ứng dây chuyền	could have cascading effects	trigger/cause cascading effects
upwelling zones	n	/ˈʌpwelɪŋ zəʊnz/	vùng nước trồi	Upwelling zones experience high acidity	coastal upwelling zones
mitigation strategies	n	/ˌmɪtɪˈɡeɪʃn ˈstrætədʒiz/	chiến lược giảm thiểu	some mitigation strategies are explored	develop/implement mitigation strategies
geoengineering	n	/ˌdʒiːəʊˌendʒɪˈnɪərɪŋ/	kỹ thuật địa cầu	such geoengineering approaches	geoengineering solutions/techniques

Bảng từ vựng chuyên ngành môi trường biển cho IELTS Reading về biến đổi khí hậu và đại dương

Passage 3 – Essential Vocabulary

Từ vựng	Loại từ	Phiên âm	Nghĩa tiếng Việt	Ví dụ từ bài	Collocation
synergistic impacts	n	/ˌsɪnəˈdʒɪstɪk ˈɪmpækts/	tác động cộng hưởng	synergistic impacts of warming and acidification	produce synergistic impacts
comprehensive transformations	n	/ˌkɒmprɪˈhensɪv ˌtrænsfəˈmeɪʃnz/	những biến đổi toàn diện	precipitating comprehensive transformations	undergo comprehensive transformations
ecological cascades	n	/ˌiːkəˈlɒdʒɪkl kæsˈkeɪdz/	các dây chuyền sinh thái	through complex ecological cascades	trigger ecological cascades
biogeochemical cycles	n	/ˌbaɪəʊdʒiːəʊˈkemɪkl ˈsaɪklz/	chu trình sinh địa hóa	alter biogeochemical cycles	affect/disrupt biogeochemical cycles
spatial distribution	n	/ˈspeɪʃl ˌdɪstrɪˈbjuːʃn/	phân bố không gian	reshape the spatial distribution	change spatial distribution
cumulative effects	n	/ˈkjuːmjʊlətɪv ɪˈfekts/	tác động tích lũy	their cumulative and interactive effects	assess cumulative effects
poleward migrations	n	/ˈpəʊlwəd maɪˈɡreɪʃnz/	di cư về phía cực	driving poleward migrations at 72km/decade	accelerate poleward migrations
taxonomic groups	n	/ˌtæksəˈnɒmɪk ɡruːps/	nhóm phân loại	not occurring uniformly across taxonomic groups	different taxonomic groups
thermal tolerances	n	/ˈθɜːməl ˈtɒlərənsɪz/	khả năng chịu nhiệt	according to their thermal tolerances	exceed thermal tolerances
no-analog communities	n	/nəʊ ˈænəlɒɡ kəˈmjuːnətiz/	cộng đồng không tương tự	formation of no-analog communities	create no-analog communities
trophic cascades	n	/ˈtrɒfɪk kæsˈkeɪdz/	dây chuyền dinh dưỡng	The trophic cascades can be disruptive	initiate trophic cascades
dietary shifts	n	/ˈdaɪətri ʃɪfts/	sự thay đổi chế độ ăn	resulted in dietary shifts for fish	cause/trigger dietary shifts
trophic downgrading	n	/ˈtrɒfɪk ˈdaʊnɡreɪdɪŋ/	sự suy giảm dinh dưỡng	triggered trophic downgrading	lead to trophic downgrading
hypoxia	n	/haɪˈpɒksiə/	thiếu oxy	Oxygen depletion, or hypoxia	experience/suffer hypoxia
metabolic demands	n	/ˌmetəˈbɒlɪk dɪˈmɑːndz/	nhu cầu trao đổi chất	increase metabolic demands	meet metabolic demands
stratification	n	/ˌstrætɪfɪˈkeɪʃn/	phân tầng	warming enhances stratification	ocean/water stratification
habitat compression	n	/ˈhæbɪtæt kəmˈpreʃn/	sự nén ép môi trường sống	This habitat compression increases vulnerability	experience habitat compression
primary productivity	n	/ˈpraɪməri ˌprɒdʌkˈtɪvəti/	năng suất sơ cấp	implications for primary productivity	affect/reduce primary productivity
euphotic zone	n	/juːˈfəʊtɪk zəʊn/	tầng ánh sáng	brings nutrients to the euphotic zone	within the euphotic zone
phytoplankton	n	/ˌfaɪtəʊˈplæŋktən/	thực vật phiêu lưu	where phytoplankton conduct photosynthesis	phytoplankton blooms/communities
marine heatwaves	n	/məˈriːn ˈhiːtweɪvz/	sóng nhiệt biển	The phenomenon of marine heatwaves	experience marine heatwaves
pernicious manifestation	n	/pəˈnɪʃəs ˌmænɪfeˈsteɪʃn/	biểu hiện có hại	particularly pernicious manifestation	pernicious manifestation of change
phenotypic plasticity	n	/ˌfiːnəˈtɪpɪk plæˈstɪsəti/	tính dẻo kiểu hình	demonstrate phenotypic plasticity	show/exhibit phenotypic plasticity
evolutionary velocity	n	/ˌiːvəˈluːʃənri vəˈlɒsəti/	tốc độ tiến hóa	may lack the evolutionary velocity	require evolutionary velocity
biological carbon pump	n	/ˌbaɪəˈlɒdʒɪkl ˈkɑːbən pʌmp/	bơm carbon sinh học	The ocean’s biological carbon pump	strengthen biological carbon pump
resilience-based management	n	/rɪˈzɪliəns beɪst ˈmænɪdʒmənt/	quản lý dựa trên khả năng phục hồi	concept of resilience-based management	adopt resilience-based management
transdisciplinary collaboration	n	/ˌtrænzdɪsəˈplɪnəri kəˌlæbəˈreɪʃn/	hợp tác liên ngành	requires transdisciplinary collaboration	foster transdisciplinary collaboration

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Kết Bài

Chủ đề “How Climate Change Is Affecting The World’s Oceans” không chỉ là một nội dung thường xuyên xuất hiện trong IELTS Reading mà còn phản ánh một trong những thách thức cấp bách nhất của nhân loại hiện nay. Qua bộ đề thi mẫu này, bạn đã được trải nghiệm đầy đủ cấu trúc của một bài thi IELTS Reading thực tế với ba passages tăng dần về độ khó.

Passage 1 giúp bạn làm quen với thông tin cơ bản về sự nóng lên của đại dương, Passage 2 đi sâu vào vấn đề axit hóa với các dạng câu hỏi yêu cầu kỹ năng paraphrase cao, và Passage 3 thách thức khả năng phân tích các khái niệm phức tạp về biến đổi hệ sinh thái biển. Tổng cộng 40 câu hỏi với 7 dạng khác nhau đã cung cấp cho bạn cơ hội luyện tập toàn diện các kỹ năng cần thiết.

Phần đáp án chi tiết kèm giải thích không chỉ cho bạn biết đáp án đúng mà còn hướng dẫn cách xác định vị trí thông tin, nhận diện paraphrase và áp dụng kỹ thuật làm bài hiệu quả. Bộ từ vựng được phân loại theo từng passage với hơn 60 từ và cụm từ quan trọng sẽ giúp bạn xây dựng vốn từ vựng học thuật vững chắc, đặc biệt hữu ích cho các chủ đề môi trường và khoa học.

Hãy nhớ rằng, thành công trong IELTS Reading không chỉ đến từ việc làm nhiều bài tập mà còn từ việc phân tích kỹ lưỡng mỗi câu trả lời sai, hiểu rõ lý do tại sao mình chọn nhầm và rút ra bài học cho những lần sau. Với đề thi mẫu chất lượng cao này, bạn đã có trong tay một công cụ luyện tập hiệu quả để tự tin bước vào phòng thi IELTS thực tế.

Chúc bạn học tập tốt và đạt được band điểm mong muốn trong kỳ thi IELTS sắp tới!