Passage 1: The Rise of Vertical Farming
You should spend about 20 minutes on Questions 1-13.
[A] By the year 2050, nearly 80% of the earth’s population will reside in urban centers. Applying the most conservative estimates to current demographic trends, the human population will increase by about 3 billion people during the interim. An estimated 109 hectares of new land (about 20% more land than is represented by the country of Brazil) will be needed to grow enough food to feed them, if traditional farming methods continue as they are practiced today. At present, throughout the world, over 80% of the land that is suitable for raising crops is in use. Historically, some of this has been laid waste by poor management practices. What remains is largely poor quality or situated in environmentally sensitive areas.
[B] One potential solution to this looming crisis is "vertical farming." The concept, popularized by Dickson Despommier, a professor at Columbia University, involves cultivating plant or animal life within skyscrapers or on vertically inclined surfaces. The idea is that instead of farming horizontally on the endless expanse of fields, we should farm upwards, utilizing the controlled environments of modern construction. A multi-storey farm in the heart of a city could hypothetically produce enough food to supply tens of thousands of citizens, drastically reducing the fossil fuels currently required to transport produce from rural farms to urban markets.
[C] The advantages of vertical farming are numerous. First, crops would be protected from weather-related failures; there would be no droughts, floods, or pests to destroy a harvest. As a result, crops could be grown year-round, multiplying the productivity of the farmed surface by a factor of 4 to 6 depending on the crop (e.g., strawberries or lettuce). Furthermore, all the water used in vertical farming can be recycled and reused, significantly reducing the massive water consumption associated with traditional agriculture. Perhaps most importantly, the controlled environment eliminates the need for herbicides, pesticides, or fertilizers, resulting in organic, chemical-free produce.
[D] However, the concept is not without its critics. The most significant hurdle is the cost of powering such facilities. While sunlight is free for traditional farmers, vertical farms require artificial lighting, usually LEDs, to mimic the sun's spectrum. Critics argue that the carbon footprint created by the energy usage of these lights, along with the climate control systems needed to regulate temperature and humidity, might outweigh the benefits of reduced transportation. Dr. Stan Cox, a senior researcher at the Land Institute, has stated that if you were to grow wheat in a vertical farm, the cost of lighting alone would make the loaf of bread prohibitively expensive.
[E] Despite the skepticism, prototypes are springing up globally. In Singapore, a country with high population density and almost no arable land, a commercial vertical farm called 'Sky Greens' produces tons of vegetables daily using a rotating hydraulic system. This system uses minimal electricity, as the rotation is powered by a water-pulley system using rainwater. Meanwhile, in Japan, a former Sony semiconductor factory has been converted into the world's largest indoor farm, using specialized LEDs that emit wavelengths optimized for plant growth, shortening the harvest cycle of lettuce from 70 days to just 40.
Passage 2: The Cognitive Benefits of Bilingualism
You should spend about 20 minutes on Questions 14-26.
[A] For decades, learning a second language was considered a burden for children. Educators and parents feared that exposure to two languages would confuse the child's mind, leading to slower development in both. However, recent research has dramatically overturned this view. Today, bilingualism is recognized not just as a social asset, but as a powerful tool for cognitive enhancement. Neuroscientists have discovered that the bilingual brain is wired differently, offering advantages that extend far beyond the ability to order coffee in Paris or Tokyo.
[B] One of the most significant findings is the concept of "executive function." This is a command system in the brain that directs the attention processes that we use for planning, solving problems, and performing various other mentally demanding tasks. Because bilinguals must constantly switch between two languages—inhibiting one to use the other—their brains are perpetually exercising this executive control system. Ellen Bialystok, a psychologist at York University in Toronto, compares it to a gym workout for the brain; the constant juggling of languages strengthens the muscles of attention and inhibition.
[C] This mental agility is evident in simple tasks. In one study, preschoolers were asked to sort cards by color (putting blue circles in a bin marked with a blue square). Both monolingual and bilingual children performed equally well. But when the rule was suddenly changed, and they were asked to sort by shape (ignoring the color), bilingual children were significantly faster at adapting to the new rule. Their brains were better equipped to block out the old, irrelevant information and focus on the new criteria.
[D] The benefits appear to persist into old age. Studies involving patients with Alzheimer’s disease have shown that bilinguals tend to develop symptoms of dementia an average of four to five years later than monolinguals. While bilingualism does not prevent the physical accumulation of plaques in the brain associated with the disease, it seems to provide a "cognitive reserve." The brain has built up enough extra connections and alternative pathways to function normally for longer, despite the underlying damage.
[E] However, the picture is not entirely positive. Some studies suggest that bilinguals may have a slightly smaller vocabulary in each language compared to a monolingual speaker of that language. They may also experience more "tip-of-the-tongue" moments, where they struggle to retrieve a specific word. Yet, researchers argue that these minor drawbacks are a small price to pay for the robust cognitive architecture that bilingualism builds.
Passage 3: The Antikythera Mechanism
You should spend about 20 minutes on Questions 27-40.
In 1900, sponge divers taking shelter from a storm off the coast of the Greek island of Antikythera discovered the wreck of an ancient Roman ship. Among the marble statues and jewelry recovered was a lump of corroded bronze and wood, which at first went unnoticed. Two years later, archaeologist Valerios Stais noticed a gear wheel embedded in the rock. This object, now known as the Antikythera Mechanism, has since been revealed to be the most sophisticated scientific instrument of the ancient world.
The mechanism dates back to around 150-100 BC. For decades, its complexity baffled historians. It contained at least 30 interlocking bronze gears, a level of technological sophistication that was not thought to have existed until the development of astronomical clocks in Europe in the 14th century—over a thousand years later. It was essentially the world's first analogue computer.
Using modern imaging technology, including X-ray tomography, researchers have reconstructed the device's function. It was hand-cranked and used to predict astronomical positions and eclipses for calendrical and astrological purposes. The front dial displayed the Greek zodiac and the Egyptian calendar. Two dials on the back displayed information about the timing of lunar and solar eclipses, and even the timing of the Panhellenic Games (including the ancient Olympics).
What makes the mechanism truly astounding is its mathematical precision. It tracked the irregular orbit of the moon (which moves faster when closer to the Earth) using a pin-and-slot mechanism that varied the speed of the gear rotation—a concept previously attributed to Kepler in the 17th century. The maker of this device possessed a grasp of astronomy and engineering that was completely lost to the West for a millennium.
The provenance of the device remains a mystery. Some suggest it may have been built by the school of Posidonius on the island of Rhodes, which was known for its astronomy. Others point to the legendary Archimedes, though he lived a century before the device's estimated construction. Regardless of its creator, the Antikythera Mechanism stands as a testament to the lost brilliance of antiquity, challenging our linear view of technological progress.
