영어 모의고사 (자동 편성)

For centuries, dreams have fascinated scientists and philosophers alike, yet no single theory fully ① explains why the sleeping brain generates such vivid and often bizarre experiences. One prominent idea suggests that dreaming helps the brain process emotional experiences, ② replays difficult events in a safe, low-stakes environment so that their emotional intensity gradually fades. Another theory proposes that dreams serve a more practical function, ③ allowing the brain to rehearse responses to threats without any real danger. Still other researchers argue that dreaming is simply a byproduct of the brain organizing memories, with vivid imagery ④ arising as the mind sorts through the day's information rather than serving any independent purpose of its own. Because these theories rest on indirect evidence, none has ⑤ been conclusively proven.

Long before a user finishes typing a sentence, the keyboard on most smartphones has already begun ① guessing what word comes next. This feature relies on a language model ② trained to notice which words commonly follow one another, so it can offer a shortlist of likely candidates above the keyboard, saving users countless keystrokes over the course of a day. The system also adapts to each individual, gradually ③ learning a person's favorite phrases, slang, and even the names of friends that no generic dictionary would recognize. This constant personalization, however, creates a subtle side effect that few users ④ notices. Because the keyboard nudges people toward its own suggestions, some linguists worry that autocomplete may be quietly narrowing everyday vocabulary, encouraging writers ⑤ to accept a convenient suggestion rather than searching for the more precise word.

Sleep hygiene refers to a set of simple daily habits that help the body prepare for consistent, ① restorative rest. Experts commonly recommend going to bed and waking up at the same time every day, even on weekends, because an irregular schedule ② clarifies the body's internal clock and makes it harder to fall asleep on demand. They also advise reserving the bedroom for sleep alone, since using the bed to study, scroll through a phone, or watch videos teaches the brain to associate that space with ③ wakeful activity rather than rest. Physical environment matters as well: a cool, dark, and quiet room tends to produce ④ deeper sleep than one that is warm, bright, or noisy. None of these individual habits guarantees a good night's sleep on its own, but together they form a routine that gradually trains the body to expect and enter sleep more easily, much the way a ⑤ consistent set of cues trains an athlete's body to perform at a certain time each day.

Climate scientists frequently warn about tipping points, thresholds beyond which a small additional change triggers a large, often irreversible shift in the climate system. Unlike ①gradual warming, which unfolds steadily over decades, crossing a tipping point can produce ②dramatic consequences within a short period. For instance, as Arctic ice melts, it exposes darker ocean water that absorbs more sunlight than reflective ice, accelerating further melting in a self-⑤reinforcing cycle. Similarly, scientists worry that a major ocean current, which currently redistributes heat across the planet, could slow dramatically if enough freshwater from melting glaciers dilutes the surrounding seawater. Once such thresholds are crossed, restoring the original balance may become nearly ③possible, even if emissions are later reduced. Therefore, researchers argue that preventing these transitions matters more than merely slowing average temperature increases. Identifying how close each system stands to its threshold remains one of the most ④urgent challenges in climate research.

When a customer opens a company's website at midnight with a billing question, an actual employee is unlikely to be available, which is exactly the gap that customer service chatbots were built to fill. These programs can instantly answer common questions, track packages, and process simple refunds without making anyone wait on hold. Yet the technology has clear boundaries. When a customer's problem is unusual, emotionally charged, or simply does not fit the chatbot's script, _______________. Many companies have responded by designing chatbots to recognize their own limits, automatically transferring a frustrated customer to a human agent.

Wearable devices that track sleep have become enormously popular, promising a detailed breakdown of light, deep, and REM sleep each night. (A) Despite these limitations, many users have come to treat the nightly score generated by their device as an objective medical verdict, sometimes experiencing anxiety when the number falls below what they expect, a phenomenon researchers have begun calling orthosomnia. (B) Independent studies comparing wearable data with polysomnography, the gold-standard method used in clinical sleep labs, have found that consumer devices are reasonably accurate at distinguishing sleep from wakefulness but considerably less reliable at identifying specific sleep stages. Some trackers overestimate deep sleep, while others underestimate the amount of time spent in REM sleep, and the margin of error can vary widely between brands. (C) These gadgets typically rely on movement sensors and heart rate monitors to estimate sleep stages, since directly measuring brain activity would require equipment found only in a sleep laboratory. This indirect approach, however, introduces significant uncertainty.

Adaptive learning apps promise something no traditional classroom can easily offer: a lesson plan that adjusts itself to each individual student in real time. (A) As a student answers practice questions, the app tracks which concepts are mastered and which remain shaky, then quietly reshuffles the next set of problems to target the weaker areas. (B) Early studies suggest that this personalized pacing can help struggling students catch up faster than a one-size-fits-all worksheet ever could. (C) However, critics caution that an app cannot replace the encouragement, humor, and flexibility a human teacher brings to a lesson.

Sleep is not a single, uniform state but a cycle that alternates between two very different modes: REM (rapid eye movement) sleep and non-REM sleep. (A) REM sleep, by contrast, brings rapid eye movements and brain activity resembling wakefulness, and is believed to help consolidate memories and process emotions. (B) A healthy night cycles through both stages several times, and disrupting either one can leave a person feeling unrested despite a full night in bed. (C) During non-REM sleep, particularly its deepest stage, the brain waves slow dramatically and the body focuses on physical repair.

주어진 문장: Not everyone, however, feels this financial burden equally, since household circumstances vary widely. The term green premium describes the extra cost that consumers must pay when they choose an environmentally friendly product or energy source over a conventional, cheaper alternative. ( ① ) For example, an electric vehicle or solar-powered appliance often carries a higher price tag than its gasoline-powered or coal-based counterpart, even though it produces fewer emissions over time. ( ② ) This price gap frequently discourages shoppers who support sustainability in principle but cannot justify the additional expense within a limited household budget. ( ③ ) In contrast, wealthier consumers can absorb the premium more easily, which creates unequal participation in green markets. ( ④ ) To narrow this gap, governments have introduced subsidies and tax credits that lower upfront costs, while companies invest in research to make clean technologies cheaper to manufacture. ( ⑤ ) As production scales up and innovation continues, many economists expect the green premium to shrink steadily, eventually making sustainable choices the more affordable option for most consumers.

주어진 문장: This gap between image and reality is precisely what makes the practice so misleading. Many companies now advertise themselves as environmentally responsible, yet a growing number of these claims turn out to be misleading. ( ① ) This practice, known as greenwashing, occurs when a business spends more effort marketing its products as eco-friendly than actually reducing environmental harm. ( ② ) A company might launch a recycled-packaging line while continuing to pollute rivers through its main factories, creating a false impression of genuine change. ( ③ ) Such tactics deceive well-intentioned consumers who wish to shop responsibly but lack the tools to verify corporate claims. ( ④ ) In contrast, truly sustainable businesses publish detailed, independently verified data about their emissions and supply chains, allowing outsiders to check their progress. ( ⑤ ) Therefore, shoppers should look beyond vague labels like green or natural and instead search for recognized certifications, transparent reports, and measurable targets. Without such scrutiny, greenwashing will keep flourishing, undermining public trust and slowing the broader shift toward an economy that truly protects the planet.