IELTS Academic Reading Practice Test 32

A The bicycle is widely regarded as one of the most efficient machines ever devised for converting human muscle into motion, and yet its history has, surprisingly, long been contested. For most of the twentieth century, popular accounts traced its lineage to a sketch attributed to Leonardo da Vinci of around 1493, supposedly showing a chain-driven two-wheeler complete with pedals. Careful examination by historians of technology in the 1990s, however, identified the sketch as a twentieth-century forgery, and the more sober consensus today places the true origins of the bicycle in the early nineteenth century. What is uncontroversial is that, in the space of roughly seventy years between 1817 and the late 1880s, a sequence of distinct vehicles emerged, each of which solved a different mechanical problem.

B The earliest accepted ancestor of the bicycle is said to be the laufmaschine, or running machine, patented in 1817 by the German aristocrat Karl von Drais. Drais's machine was a wooden frame on two wheels, with no pedals; the rider sat astride it and pushed himself along the ground with alternating feet. The vehicle's chief contribution was not propulsion but balance: it demonstrated, against contemporary common sense, that a person could remain upright on two in-line wheels while in motion. The laufmaschine briefly attracted enthusiastic riders in Western Europe and the United States but was soon dismissed as an aristocratic curiosity, and serious development of two-wheeled vehicles paused for nearly half a century.

C The decisive next step is widely held to have been the addition of pedals. In 1863, the French coachbuilder Pierre Michaux and his son Ernest attached cranks and pedals directly to the front wheel of a Drais-style frame, producing what came to be known as the velocipede or, more memorably, the boneshaker — a nickname earned from its iron-tyred wooden wheels and unsprung wrought-iron frame, which transmitted every irregularity of the cobbled road to the rider's body. Despite this discomfort, the Michaux velocipede was an immediate commercial success. By the late 1860s, dedicated factories had appeared in France, Britain and the eastern United States, and the new sport attracted thousands of subscribers to clubs that held races, parades and long-distance excursions.

D The mechanical limitation of the velocipede was that one turn of the pedals produced only one turn of the wheel, capping the rider's top speed at a few kilometres per hour above walking pace. The British engineer James Starley solved this in 1870 by enlarging the front wheel dramatically and shrinking the rear, producing the famous "ordinary" or penny-farthing. With a front wheel often measuring 1.4 metres in diameter, a single revolution carried the rider four to five metres forward, and racing cyclists were soon reaching speeds of 30 kilometres per hour. The price of this performance was instability and danger. The rider sat almost directly above the front axle, and a sudden stop could pitch him forwards over the handlebars, an accident known to enthusiasts as the "header." Penny-farthings remained the dominant sporting bicycles of the 1880s but were practical only for athletic young men.

E The design that would supplant the penny-farthing emerged from James Starley's nephew, John Kemp Starley, who introduced the Rover safety bicycle in 1885. Starley's machine returned to two wheels of similar size, transferred power to the rear wheel through a chain drive of his own refinement and set the rider in the upright, low-saddled position that has remained standard. The new design lost no speed in comparison with the penny-farthing because the chain ratio allowed the rear wheel to turn several times for each rotation of the pedals; it was, in addition, very much safer and accessible to a wider public, including women in long skirts. When John Boyd Dunlop's pneumatic tyre was added in 1888, the bicycle in essentially its modern form was complete.

F The years immediately after 1888 saw what contemporary observers called a "bicycle boom." In the United States alone, output rose from about 200,000 machines a year in 1889 to over a million by 1899, and prices fell from $150 to under $30 in the same decade. Cycling clubs successfully lobbied for the paving of rural roads — anticipating, ironically, the smooth surfaces that would later be claimed by the motor car. Public health writers credited the bicycle with restoring fresh-air recreation to crowded cities, while suffragists, led most prominently by the American campaigner Susan B. Anthony, hailed it as a vehicle of female emancipation. The bicycle remains the principal personal transport of perhaps a billion people worldwide, and it has periodically been rediscovered as a near-ideal solution to urban congestion and to the carbon emissions of car-based transport.

A Amphibians — the frogs, toads, salamanders and caecilians — are widely regarded as among the oldest of the vertebrate groups, having been present on Earth for some 365 million years. They have survived multiple mass extinction events, including the asteroid impact that ended the age of the dinosaurs. Today, however, they are vanishing at a rate without modern precedent. The International Union for Conservation of Nature estimates that approximately 41 percent of all known amphibian species are currently threatened with extinction, a figure that exceeds the equivalent proportions for mammals (25 percent) or birds (13 percent). The phenomenon appears to be global. Declines have been reported from the high Andes, from the rainforests of Central America and Madagascar, from European wetlands and even from undisturbed mountain streams in eastern Australia.

B The first scientific alarm is said to have been sounded at the First World Congress of Herpetology, held in 1989 at the University of Kent. Researchers from around the world independently reported sudden disappearances of frog populations from sites that had been carefully studied for decades. Initially the reports were met with some scepticism — amphibian populations are notoriously prone to large natural fluctuations — but a coordinated review published in the journal Conservation Biology in 1991 documented declines at 47 of 65 long-term study sites. The pattern was too widespread to be dismissed as ordinary variation.

C The single most destructive agent identified to date is widely held to be a microscopic chytrid fungus, Batrachochytrium dendrobatidis, commonly abbreviated as Bd. The pathogen, first described in 1998 by a team led by Joyce Longcore at the University of Maine, infects the keratin-containing skin of adult amphibians. Because amphibians breathe and regulate water exchange through their skin, the infection disrupts these vital functions and is fatal within a few weeks. Bd has now been recorded in more than 60 countries and 500 species. Phylogenetic analyses published in 2018 traced the most virulent global lineage of the fungus to the Korean peninsula, from which it appears to have spread through the worldwide trade in amphibian pets, food and laboratory animals.

D Habitat loss has reinforced and in many cases preceded the chytrid epidemic. Amphibians generally depend on the close juxtaposition of aquatic breeding sites and the moist terrestrial habitats in which adults forage and overwinter; agricultural drainage and urban expansion have steadily eroded both. A 2019 review by Russell Hawkins and colleagues estimated that more than 60 percent of the world's wetlands have been destroyed since 1900. In tropical regions the principal driver appears to be the conversion of forest to cropland, while in temperate Europe and North America the drainage of small ponds and channelisation of streams have reduced both connectivity and breeding success.

E Pesticides and other agricultural chemicals reportedly impose more subtle but pervasive pressures. Amphibian larvae, which spend their early lives in shallow standing water, are particularly susceptible to dissolved contaminants. Field experiments at the University of California, Berkeley, have shown that atrazine, one of the world's most widely used herbicides, can disrupt sexual development at concentrations several hundred times lower than the legal drinking-water limit, producing male frogs with ovaries and reduced reproductive viability. Roadway runoff, fertiliser-rich agricultural drainage and pharmaceuticals excreted into wastewater have all reportedly been implicated.

F Climate change is widely regarded as an increasingly serious additional stressor. Amphibians, as ectotherms, are highly sensitive to changes in temperature and moisture. In Central America, the disappearance of the golden toad (Incilius periglenes) from the cloud forests of Costa Rica was attributed in part to an upward shift in the cloud base, which dried out the habitat the species required. In northern latitudes, warmer winters have caused some species to emerge from hibernation before the insects on which they feed are available. In Australia, prolonged droughts have already eliminated several local frog populations from waterholes that have remained dry for years.

G A particularly significant complication is that several of these pressures interact in ways that are more damaging than the sum of their parts. Climate change appears to alter the geographic range over which Bd can thrive, while habitat fragmentation reduces the ability of amphibian populations to escape into refugia. Field studies in the Pyrenees and the Sierra Nevada of California have shown that warmer temperatures correspond closely with increased Bd-related mortality in midwife toads and yellow-legged frogs respectively. Disentangling such interacting drivers has become one of the central methodological challenges of the field.

H Conservation responses have proliferated in recent years. Captive breeding programmes have been established for the most acutely threatened species; the Atlanta Botanical Garden in the United States and the Durrell Wildlife Conservation Trust on Jersey now maintain dozens of frog and salamander species that have effectively disappeared from the wild. Probiotic treatments, in which beneficial bacteria are applied to frogs' skin to suppress Bd colonisation, have shown promising results in laboratory trials. Strict biosecurity protocols govern the international amphibian trade in several countries, though compliance is uneven. Beyond these interventions, the broader prescription is familiar: protect and restore wetlands, regulate the most damaging agricultural chemicals, slow the warming of the climate, and treat amphibians as the sentinel species their physiology makes them.

A The modern office is younger than most of its occupants imagine. As recently as the early twentieth century, clerical work was conducted in arrangements borrowed essentially unaltered from the workshop: long rows of identical desks supervised from a raised platform, in rooms lit by large windows and ventilated only by their occupants' breath. The transformation of these spaces into objects of explicit study by ergonomists and designers can be traced to a handful of decisive interventions.

B The first thinker to apply a self-consciously scientific approach to office work is said to have been the American engineer Frederick Winslow Taylor, whose 1911 book The Principles of Scientific Management proposed that every clerical task should be analysed into its elementary motions and standardised across the workforce. Taylor's prescriptions encouraged the spread of large, undivided rooms in which managers could observe many clerks at once. The Larkin Administration Building, designed by Frank Lloyd Wright and opened in Buffalo in 1906, embodied an early version of this ideal: 1,800 employees worked at uniformly spaced desks on five glass-roofed floors arranged around a central atrium. Wright did, however, introduce features that pointed beyond Taylor — purpose-built furniture, mechanical ventilation and a hint of acoustic awareness.

C The next major shift was the post-war flowering of the European "office-landscape" movement, or Burolandschaft, developed by the Quickborner consulting group in West Germany during the 1950s. Burolandschaft replaced the regimented rows of the Taylorist office with an organic arrangement of desks, plants and low partitions intended to reflect the actual patterns of communication between workers. Quickborner's designers drew on the observation that information flow follows social rather than hierarchical lines. The principles were exported widely during the 1960s, although the open-plan approach in practice often shed the carefully studied flexibility of Quickborner in favour of the simple cost savings of removing internal walls.

D The 1968 launch by Herman Miller of the Action Office II system, designed by Robert Propst, introduced what was originally intended as a more humane and adaptable form of open-plan working. Propst's system used freestanding partition panels of varying height that could be reconfigured as work changed; the panels also supported tackable surfaces, storage and lighting. The system was an immediate commercial success, but in its widespread adoption from the 1970s onwards it was simplified into uniform "cubicles" that lost the carefully considered variability of the original. Propst himself, late in life, expressed regret at what he called the "monolithic insanity" into which his idea had been compressed.

E Modern office ergonomics rests on a far more detailed understanding of the human body at work. Studies at Cornell University and at NIOSH, the United States National Institute for Occupational Safety and Health, have shown that prolonged seated work in poorly adjusted chairs contributes to musculoskeletal disorders accounting for a substantial fraction of all workplace medical claims. The recommended posture — feet flat on the floor, thighs roughly parallel to the ground, eyes at the top of the screen, wrists straight — assumes adjustable seat height, lumbar support and a screen tilted to between 10 and 20 degrees below the horizontal. The standing desk, popular in the 2010s, has been shown to relieve some of the pressures of seated work but is widely considered no panacea: standing for prolonged periods produces its own pattern of fatigue and circulatory problems.

F Lighting and acoustics have attracted increasing attention since the early 2000s. Excessive artificial illumination has been linked to headaches and reduced alertness, while light that is too dim produces eyestrain. The 2018 update to the European EN 12464 standard recommended task-area illumination of around 500 lux for general office work. Acoustic privacy has emerged as a particular concern in open-plan environments; a 2013 review by Jungsoo Kim and Richard de Dear at the University of Sydney found that around half of all employees in fully open layouts reported dissatisfaction with their acoustic conditions, compared with around 16 percent of those in enclosed offices.

G The COVID-19 pandemic of 2020 disrupted the assumptions of office ergonomics more severely than any event since the early twentieth century. Millions of workers relocated to home offices that had not been designed as such, and the resulting wave of musculoskeletal complaints prompted employers to reassess what they owed their staff. Many organisations have settled on a hybrid model in which workers attend the office on selected days and otherwise work from home, often with employer-supplied chairs and monitors. A 2023 survey by the consultancy Leesman found that 71 percent of workers reported being more productive at home than in their employer's office, although a substantial minority — particularly those at the early stages of their careers — preferred the in-person environment for mentorship.

H The ergonomics of the office, taken as a whole, illustrates the difficulty of designing a space that must serve heterogeneous purposes, occupants and tasks. Heat, noise, light, posture and individual preference all have to be balanced against one another, and the balance shifts as the work itself evolves. No single layout, however carefully studied, will suit every worker; what has emerged from a century of experimentation is the principle that successful offices give their occupants meaningful control over the conditions in which they work.