Sobre este conjunto: armado y ligeramente editado a partir de pasajes reales recordados por candidatos. IELTS utiliza un banco global de preguntas, por lo que estos pasajes circulan en todo el mundo. Para darte una prueba completa y lista para rendir, se agrupan pasajes reportados en el mismo periodo — por lo tanto, un conjunto puede combinar pasajes de varias fechas de examen, no de una sola sesión. Organizado para tu comodidad de estudio. Basado en recuerdos de candidatos — no es material oficial de IELTS.
Reading Passage 1: Triumph of the City
Triumph of the City, by Edward Glaeser, is a thrilling and very readable hymn of praise to an invention so vast and so effective that it is generally taken for granted. More than half the global population already live in urban areas and, every month, five million more flood into the cities of the developed and developing worlds. The crowds and poverty of some of these modern cities may horrify us. They shouldn’t, says Glaeser; they are signs of growth, energy and aspiration. Cities are our best and brightest hope.
This idea has had more than two hundred years of resistance. Not long after the Industrial Revolution began in Britain, the Romantic poets turned away from the smoke and factories of their cities to celebrate the air and light of untouched nature. In 19th-century America, the writer Henry David Thoreau retreated to the wilderness of Walden Pond to live the solitary, simple life, and convinced generations of Americans that cities were bad and nature was good.
They had, Glaeser admits, a point. The early industrial cities were dirty, since they lacked efficient waste-disposal systems, and disease spread rapidly among the population. But more importantly they were profitable, and there were enormous commercial incentives to make them work, as well as political ones. Their transformation could be achieved at a stroke: in the second half of the 19th century, the French Emperor Napoleon III gave Baron Haussmann unrestricted power to turn the slum-infested city of Paris into one of the wonders and delights of the modern world. Or the transformation could be done by trial and error. Glaeser gives a brilliant account of the stop-start progression of New York to its late 20th-century position as the cultural and economic centre of the world. Either way, Paris, New York and other cities developed because they were truly effective markets of ideas and innovation.
For these and many other reasons, we should not be so upset by the spectacle of urban poverty. The poor flock to cities in the hope of becoming richer (which, by and large, they do). They also reinvigorate the economy of the city. It is folly to drive them away by forcing property prices to soar with unreasonable planning regulations. Instead, cities should build more houses and thereby hold property prices in check.
It can go wrong, of course. In Glaeser’s view, this is primarily because municipal authorities fail to understand the principal virtues of their cities. The heart of Paris, as many Parisians say, is turning into a museum because of the desire to preserve Baron Haussmann’s 19th-century boulevards. Glaeser defends their preservation, but argues that in the 1950s the French made a mistake in establishing a huge high-rise commercial development — La Défense — on the outskirts of the city. Far better, he says, to have turned the central area of Montparnasse into a new commercial district. This would have revitalised much of the city centre without destroying its fabric. In India, Mumbai could save itself from ever-more inefficient sprawl over the surrounding area simply by relaxing the rules presently imposed on the height of new constructions.
In America, it is the suburbs that have proved to be the real disaster. Glaeser is repentant on this subject himself. He moved to the suburbs when he had children. His entirely legitimate excuse is that the government made him (and millions like him) do it. By under-taxing petrol and imposing tight planning restrictions on inner cities that drove up the cost of property, it made flight to the suburbs more or less inevitable for the middle classes.
This is a disaster because nothing is more inefficient than a suburb. Suburbanites mingle less, and lose the face-to-face contact that makes being an urbanite so much more creative. Moreover, houses are costlier to heat and cool than flats, and suburbanites drive thousands more miles per year than city dwellers. Every aspect of life involves more consumption. This leads to the strongest and newest argument in favour of cities — they are good for the environment. To live in the country or the suburbs is to have a vastly larger carbon footprint than any urbanite.
Full of characters and accessible information, this is a tremendous book, not least because, like me, you will find yourself constantly seeking reasons to disagree. Like the poor in the city, this is a sign of success. If you hate the city and get moist-eyed at the thought of the country then, one way or another, Glaeser is the man you will have to take on.
- 1
Problems with early cities – dirt – 1 _______ but there were commercial and 2 _______ reasons for improving them
- 2
Urban poverty is not a major problem because poor people – generally get 3 _______ – help to develop the urban 4 _______
- 3
Cities do have some problems – e.g. – the centre of Paris is becoming a 5 _______ – Mumbai is negatively affected by height restrictions on new buildings.
- 4
In the US, the middle classes have moved to the suburbs due to – cheap petrol – high 6 _______ prices in inner cities
- 5
Disadvantages of suburbs – less personal 7 _______ – increased 8 _______ of resources such as heating – which damages the environment
- 6
Glaeser believes that congestion and poverty in some modern cities indicate serious problems.
- A. TRUE
- B. FALSE
- C. NOT GIVEN
- 7
The writer Henry David Thoreau discussed the ideas of the Romantic poets in his work.
- A. TRUE
- B. FALSE
- C. NOT GIVEN
- 8
Emperor Napoleon III was influenced by the complaints of poor people living in Paris.
- A. TRUE
- B. FALSE
- C. NOT GIVEN
- 9
Strict planning regulations may be beneficial for a city’s development.
- A. TRUE
- B. FALSE
- C. NOT GIVEN
- 10
Glaeser argues that the location of commercial development at La Défense was a bad idea.
- A. TRUE
- B. FALSE
- C. NOT GIVEN
Reading Passage 2: The Secret Language of Plants
For a long time, scientists regarded plants as silent and passive organisms, limited to responding mechanically to sunlight, gravity, and water. Yet, growing evidence now challenges this perception. Researchers have discovered that many plants can "communicate" with one another through the release of airborne chemical signals. When attacked by herbivorous insects, trees such as willows, poplars, and maples emit volatile organic compounds (VOCs) that alert nearby plants to danger. These neighboring plants, upon receiving the signal, begin producing chemicals that make their leaves less appetizing or even toxic to insects. In effect, they seem to "warn" one another of incoming threats.
This idea, once dismissed as science fiction, was first proposed in 1983 when two independent studies demonstrated that uninjured trees growing near damaged ones were capable of activating their own defense mechanisms. Although early critics labeled the findings as flawed or exaggerated, further research has since revived the concept. Modern experiments, conducted both in laboratories and in natural ecosystems, have repeatedly confirmed that plant signaling is a genuine biological process. Ecologist Richard Karban from the University of California, Davis, estimates that roughly forty out of forty-eight studies have found positive evidence for interplant communication.
Richard Karban's journey into this mysterious world began not with plants, but with insects. As a young ecologist, he studied how trees cope with infestations of cicadas and caterpillars. During that time, most biologists assumed that plants survived mainly through endurance, tolerating harsh conditions without active responses. However, in the early 1980s, zoologist David Rhoades discovered that plants could defend themselves more dynamically. By altering the chemical composition of their leaves, plants made them less nutritious to herbivores. What surprised Rhoades even more was that uninjured willows located near infested ones also produced these defensive compounds. The conclusion was startling: plants were somehow sensing signals from their neighbors. The excitement grew when similar results were found in poplars and sugar maples by scientists Ian Baldwin and Jack Schultz. Popular media soon proclaimed the discovery of "talking trees," though such headlines made many researchers skeptical, fearing that the field was becoming pseudoscientific.
Nevertheless, further evidence accumulated. In the sagebrush-covered slopes of northern California, Karban simulated insect attacks by clipping plant leaves. He observed that nearby wild tobacco plants, unrelated to sagebrush, began producing protective enzymes such as polyphenol oxidase. These plants later showed significantly less leaf damage from grasshoppers and caterpillars. The experiment provided strong proof that interplant signaling could occur naturally, not just under laboratory conditions.
By the 1990s, the idea of chemical communication among plants gained new support from scientists like Ted Farmer at the University of Lausanne. Working initially with sagebrush and tomato plants, Farmer demonstrated that when damaged sagebrush leaves were sealed in jars with undamaged tomato plants, the tomatoes began releasing proteinase inhibitors—substances that disrupt insect digestion. This indicated that plants could indeed send and receive airborne messages.
Subsequent research revealed that almost every green plant produces a unique cocktail of volatile compounds. The scent of freshly cut grass, for example, is actually a complex mixture of alcohols, aldehydes, and ketones—alarm signals that warn neighboring plants of damage. Lima beans respond to chemicals emitted by other lima beans being eaten, corn seedlings prepare themselves against caterpillars, and even chili peppers react to the emissions of cucumber plants. Insects, too, are part of this invisible communication network: maize attacked by beet armyworms releases volatiles that attract parasitic wasps, which lay their eggs in the caterpillars' bodies. Thus, plants not only "talk" to one another but also recruit animal allies in their defense.
Farmer later discovered that plants can transmit internal messages using electrical pulses, similar to the way animals send nerve signals. Though plants lack brains or neurons, this voltage-based signaling suggests an unexpected level of biological sophistication. As Farmer remarked, "The more we study plants, the more we realize how intelligent their systems truly are."
Despite mounting evidence, not all scientists agree that plants are truly communicating. Some argue that what appears to be communication might simply be a form of eavesdropping. A plant might release chemicals into the air as part of its own defense, and nearby plants, detecting these volatiles, may respond independently. According to ecologist Martin Heil, most of these chemical signals travel no more than a meter, suggesting that plants may primarily be signaling to themselves rather than intentionally warning others. In this view, "plant communication" might be better understood as self-signaling with unintended recipients.
Still, the evolutionary implications are significant. If plants can share biochemical information, they may coordinate defenses across entire populations. This could have profound ecological and agricultural applications. For instance, certain modern corn hybrids have lost their ancestral ability to produce volatiles that attract beneficial wasps. Reintroducing these traits could make crops more resistant to pests, reducing the need for chemical pesticides. Other possibilities include planting "sentinel" species—plants with highly sensitive signaling systems—among crops, allowing them to act as early warning systems.
Whether we call it communication, signaling, or eavesdropping, the phenomenon challenges long-held distinctions between plants and animals. Plants respond, adapt, and interact with one another in ways that suggest a hidden intelligence within ecosystems. As scientists continue decoding these silent messages, they are beginning to view the natural world as a living web of signals and responses—a world far more dynamic and connected than we ever imagined.
- 11
When insects attack, plants release .................... that can alert their neighbours.
- 12
According to Karban, sagebrush and wild tobacco respond to these signals by producing .................... to defend themselves.
- 13
Early studies on talking trees were dismissed because they were thought to be .................... or unrealistic.
- 14
The smell of .................... is actually a distress signal for plants rather than just a pleasant scent.
- 15
Some scientists believe that plants communicating with others may just be .................... on their own signals.
- 16
What was David Rhoades' main finding in 1983?
- A. Insects prefer feeding on trees far from infested ones.
- B. Damaged willows send messages to nearby undamaged ones.
- C. Tent caterpillars ignore biochemical changes in leaves.
- D. Infested trees grow faster to survive attack.
- 17
What was the major reason early scientists were skeptical about plant communication?
- A. The concept seemed too extraordinary to be real.
- B. The plants studied were already genetically modified.
- C. The results contradicted established chemical theories.
- D. Researchers found no evidence in laboratory experiments.
- 18
According to the text, what did Ted Farmer discover about plant communication?
- A. Plants use sound waves to transmit information.
- B. Plants can send electrical pulses similar to animal nerve signals.
- C. Certain trees communicate through underground roots.
- D. Plants communicate only under laboratory conditions.
- 19
What practical use could the study of plant communication have?
- A. Developing fertilizers that make plants grow faster.
- B. Reducing insects that destroy wild forests.
- C. Helping crops defend themselves naturally against pests.
- D. Increasing the number of species in agricultural lands.
- 20
He conducted experiments in the wild that supported the idea of chemical communication among plants.
- A. Richard Karban
- B. Ted Farmer
- C. Ian Baldwin
- D. David Rhoades
- E. Martin Heil
- 21
He discovered that plants use an electrical system similar to the animal nervous system.
- A. Richard Karban
- B. Ted Farmer
- C. Ian Baldwin
- D. David Rhoades
- E. Martin Heil
- 22
He argued that plants may simply be responding to their own chemical emissions.
- A. Richard Karban
- B. Ted Farmer
- C. Ian Baldwin
- D. David Rhoades
- E. Martin Heil
- 23
He first suggested that plants could communicate through airborne signals.
- A. Richard Karban
- B. Ted Farmer
- C. Ian Baldwin
- D. David Rhoades
- E. Martin Heil
Reading Passage 3: Living Dunes
When you think of a sand dune, you probably picture a barren pile of lifeless sand. But sand dunes are actually dynamic natural structures. They grow, shift and travel. They crawl with living things. Some sand dunes even sing.
A Although no more than a pile of wind-blown sand, dunes can roll over trees and buildings, march relentlessly across highways, devour vehicles on its path, and threaten crops and factories in Africa, the Middle East, and China. In some places, killer dunes even roll in and swallow up towns. Entire villages have disappeared under the sand. In a few instances the government built new villages for those displaced only to find that new villages themselves were buried several years later. Preventing sand dunes from overwhelming cities and agricultural areas has become a priority for the United Nations Environment Program.
B Some of the most significant experimental measurements on sand movement were performed by Ralph Bagnold, a British engineer who worked in Egypt prior to World War II. Bagnold investigated the physics of particles moving through the atmosphere and deposited by wind. He recognised two basic dune types, the crescentic dune, which he called “barchan,” and the linear dune, which he called longitudinal or “sief” (Arabic for “sword”). The crescentic barchan dune is the most common type of sand dune. As its name suggests, this dune is shaped like a crescent moon with points at each end, and it is usually wider than it is long. Some types of barchan dunes move faster over desert surfaces than any other type of dune. The linear dune is straighter than the crescentic dune with ridges as its prominent feature. Unlike crescentic dunes, linear dunes are longer than they are wide — in fact, some are more than 100 miles (about 160 kilometers) long. Dunes can also be comprised of smaller dunes of different types, called complex dunes.
C Despite the complicated dynamics of dune formation, Bagnold noted that a sand dune generally needs the following three things to form: a large amount of loose sand in an area with little vegetation— usually on the coast or in a dried-up river, lake or sea bed; a wind or breeze to move the grains of sand; and an obstacle, which could be as small as a rock or as big as a tree, that causes the sand to lose momentum and settle. Where these three variables merge, a sand dune forms.
D As the wind picks up the sand, the sand travels, but generally only about an inch or two above the ground, until an obstacle causes it to stop. The heaviest grains settle against the obstacle, and a small ridge or bump forms. The lighter grains deposit themselves on the other side of the obstacle. Wind continues to move sand up to the top of the pile until the pile is so steep that it collapses under its own weight. The collapsing sand comes to rest when it reaches just the right steepness to keep the dune stable. The repeating cycle of sand inching up the windward side to the dune crest, then slipping down the dune’s slip face allows the dune to inch forward, migrating in the direction the wind blows.
E Depending on the speed and direction of the wind and the weight of the local sand, dunes will develop into different shapes and sizes. Stronger winds tend to make taller dunes; gentler winds tend to spread them out. If the direction of the wind generally is the same over the years, dunes gradually shift in that direction. But a dune is “a curiously dynamic creature”, wrote Farouk El-Baz in National Geographic. Once formed, a dune can grow, change shape, move with the wind and even breed new dunes. Some of these offspring may be carried on the back of the mother dune. Others are born and race downwind, outpacing their parents.
F Sand dunes even can be heard ‘singing’ in more than 30 locations worldwide, and in each place the sounds have their own characteristic frequency, or note. When the thirteenth century explorer Marco Polo encountered the weird and wonderful noises made by desert sand dunes, he attributed them to evil spirits. The sound is unearthly. The volume is also unnerving. Adding to the tone’s otherworldliness is the inability of the human ear to localise the source of the noise. Stéphane Douady of the French national research agency CNRS and his colleagues have been delving deeper into dunes in Morocco, Chile, China and Oman, and believe they can now explain the exact mechanism behind this acoustic phenomenon.
G The group hauled sand back to the laboratory and set it up in channels with automated pushing plates. The sands still sang, proving that the dune itself was not needed to act as a resonating body for the sound, as some researchers had theorised. To make the booming sound, the grains have to be of a small range of sizes, all alike in shape: well-rounded. Douady’s key discovery was that this synchronised frequency— which determines the tone of sound— is the result of the grain size. The larger the grain, the lower the key. He has successfully predicted the notes emitted by dunes in Morocco, Chile and the US simply by measuring the size of the grains they contain. Douady also discovered that the singing grains had some kind of varnish or a smooth coating of various minerals: silicon, iron and manganese, which probably formed on the sand when the dunes once lay beneath an ancient ocean. But in the muted grains this coat had been worn away, which explains why only some dunes can sing. He admits he is unsure exactly what role the coating plays in producing the noise. The mysterious dunes, it seems, aren’t quite ready yet to give up all of their secrets.
- 24
27 Paragraph A .......................
- i. shaping and reforming
- ii. causes of desertification
- iii. need combination of specific conditions
- iv. potential threat to industry and communication
- v. an old superstition demystified
- vi. differences and similarities
- vii. a continuous cycling process
- viii. habitat for rare species
- ix. replicating the process in laboratory
- x. commonest type of dune
- 25
28 Paragraph B .......................
- i. shaping and reforming
- ii. causes of desertification
- iii. need combination of specific conditions
- iv. potential threat to industry and communication
- v. an old superstition demystified
- vi. differences and similarities
- vii. a continuous cycling process
- viii. habitat for rare species
- ix. replicating the process in laboratory
- x. commonest type of dune
- 26
29 Paragraph C .......................
- i. shaping and reforming
- ii. causes of desertification
- iii. need combination of specific conditions
- iv. potential threat to industry and communication
- v. an old superstition demystified
- vi. differences and similarities
- vii. a continuous cycling process
- viii. habitat for rare species
- ix. replicating the process in laboratory
- x. commonest type of dune
- 27
30 Paragraph D .......................
- i. shaping and reforming
- ii. causes of desertification
- iii. need combination of specific conditions
- iv. potential threat to industry and communication
- v. an old superstition demystified
- vi. differences and similarities
- vii. a continuous cycling process
- viii. habitat for rare species
- ix. replicating the process in laboratory
- x. commonest type of dune
- 28
31 Paragraph E .......................
- i. shaping and reforming
- ii. causes of desertification
- iii. need combination of specific conditions
- iv. potential threat to industry and communication
- v. an old superstition demystified
- vi. differences and similarities
- vii. a continuous cycling process
- viii. habitat for rare species
- ix. replicating the process in laboratory
- x. commonest type of dune
- 29
32 Paragraph F .......................
- i. shaping and reforming
- ii. causes of desertification
- iii. need combination of specific conditions
- iv. potential threat to industry and communication
- v. an old superstition demystified
- vi. differences and similarities
- vii. a continuous cycling process
- viii. habitat for rare species
- ix. replicating the process in laboratory
- x. commonest type of dune
- 30
33 Paragraph G .......................
- i. shaping and reforming
- ii. causes of desertification
- iii. need combination of specific conditions
- iv. potential threat to industry and communication
- v. an old superstition demystified
- vi. differences and similarities
- vii. a continuous cycling process
- viii. habitat for rare species
- ix. replicating the process in laboratory
- x. commonest type of dune
- 31
34 ________ dune is said to have long ridges that can extend hundreds of miles.
- 32
35 According to Bagnold, an ________ is needed to stop the sand from moving before a dune can form.
- 33
36 Stéphane Douady believes the singing of dunes is not a spiritual phenomenon, but purely ________.
- 34
37 There are many different types of dunes, two of which are most commonly found in deserts throughout the world, the linear dune and the 37............................ dune, sometimes also known as the crescentic dune.
- 35
38 To produce singing sand in lab, all the sands must have similar 38............................ .
- 36
39 And scientists have discovered that the size of the sand can affect the 39............................ of the sound.
- 37
40 But the function of the varnish composed by a mixture of 40............................ still remains puzzling.
Mostrar clave de respuestas
Clave de respuestas
1. disease / political
2. richer / economy
3. museum
4. property
5. contact / consumption
6. FALSE
7. NOT GIVEN
8. NOT GIVEN
9. FALSE
10. TRUE
11. chemical signals
12. protective enzymes
13. flawed
14. cut grass
15. eavesdropping
16. B
17. A
18. B
19. C
20. A
21. B
22. E
23. D
24. iv
25. x
26. iii
27. vii
28. i
29. v
30. ix
31. linear
32. obstacle
33. acoustic
34. barchan
35. shape
36. tone
37. minerals