영어 모의고사 (자동 편성)

Melatonin is a hormone ① produced by a small gland deep within the brain, and its release follows a remarkably predictable daily pattern. Levels stay low throughout the bright hours of the day, ② begin rising in the evening as darkness falls, peak in the middle of the night, and then decline again as morning approaches. This rhythm is controlled primarily by light: specialized cells in the eye detect brightness and send signals that either permit or ③ suppress melatonin production, which is why exposure to bright screens late at night can delay its release and make falling asleep more difficult. Unlike some hormones that directly cause the body to perform a task, melatonin does not force sleep to occur; instead, it signals to the rest of the body that night has arrived, ④ preparing various systems to shift into a lower-energy state. Because of this signaling role, taking melatonin supplements at the wrong time can shift a person's internal clock in the opposite direction from what was ⑤ intending.

Modern factories increasingly rely on collaborative robots, often called cobots, ①which are designed to work safely alongside human employees. Unlike traditional industrial robots that operate behind safety cages, cobots use sensors ②detect nearby workers and adjust their movements accordingly. In practice, cobots typically handle repetitive or physically demanding tasks, such as ③lifting heavy parts, while human workers focus on tasks that require judgment. This division of labor increases overall efficiency, since each side ④contributes what it does best. Manufacturers who have introduced cobots report fewer workplace injuries, largely because employees no longer ⑤perform exhausting repetitive motions all day.

VO2 max, defined as the maximum volume of oxygen a person's body can consume and use during intense exercise, is widely regarded as one of the best single indicators of cardiorespiratory fitness. Elite endurance athletes typically post VO2 max values far ① higher than those of untrained individuals, reflecting hearts that pump larger volumes of blood and muscles that extract oxygen from that blood with remarkable efficiency. While genetics accounts for a substantial portion of an individual's potential VO2 max, consistent aerobic training can still ② raise the measurement considerably over months of dedicated effort. Interval training, which alternates short bursts of near-maximal effort with periods of recovery, has proven particularly ③ effective at improving this measurement compared to steady, moderate-intensity exercise alone. It is worth noting, however, that a high VO2 max does not guarantee success in competition, since factors such as running economy, pacing strategy, and mental resilience also play a ④ decisive role in determining who actually crosses the finish line first. These additional factors remain ⑤ irrelevant to overall performance.

Self-driving technology is advancing rapidly, and its impact on the transportation industry is becoming increasingly ①visible. Companies are testing autonomous trucks that can travel long distances without human drivers, potentially ②transforming how goods move across countries. Millions of professional drivers worry about losing their jobs as automation ③spreads through the industry. Experts predict that certain driving jobs, particularly long-distance trucking, may shrink significantly within the next two decades. However, new roles are also ④emerging, including remote vehicle operators who monitor fleets of autonomous trucks. Workers who adapt their skills toward supervising and maintaining these systems are likely to find new opportunities rather than face ⑤employment.

Only a decade ago, translation apps produced sentences so awkward that users often laughed at the results. Today, many of these apps rely on neural networks that analyze entire sentences at once, capturing context instead of translating word by word. This shift has made everyday tasks such as reading a foreign menu or chatting with an overseas friend remarkably smooth. Even so, the technology still struggles with humor, sarcasm, and cultural nuance, so that _______________. For this reason, professional translators argue that these apps are best treated as a helpful starting point rather than a final, polished result.

Companies have discovered that ordinary advertisements no longer capture the attention of young consumers as effectively as they once did. (A) As a result, many brands now spend a large portion of their advertising budgets on influencer partnerships rather than television commercials. (B) This is because influencers build long-term relationships with their audiences, which makes recommendations feel personal rather than commercial. (C) However, brands must choose their partners carefully, since an influencer's reputation can directly affect how a product is perceived.

Across many countries, high schools begin classes early in the morning, often before eight o'clock. (A) Researchers who study this mismatch argue that the underlying problem is not laziness or poor discipline among students, but a scheduling system built around adult rhythms rather than adolescent ones. (B) This schedule assumes that teenagers can simply go to bed earlier to compensate, but biology tells a different story, because the body's internal clock shifts later during adolescence, delaying the release of melatonin until well after ten at night. (C) As a result, most teenagers are not physiologically ready to fall asleep until much later than adults, and when early start times force them to wake before completing a full sleep cycle, the mismatch accumulates into a chronic sleep debt.

Amateur athletes often credit this kind of guidance with helping them train more consistently without pushing their bodies too hard. A smartwatch strapped to a runner's wrist can now do far more than simply count steps; it monitors heart rate variability, running form, and recovery time, then uses that data to suggest a training plan tailored to the individual rather than a generic weekly schedule. ( ① ) When the device detects signs of overtraining, such as an unusually high resting heart rate several mornings in a row, it may recommend a lighter workout or an extra rest day before fatigue turns into an actual injury. ( ② ) Sports scientists note an important caveat, however. ( ③ ) A wrist-based sensor cannot fully capture the same physiological detail available in a professional lab. ( ④ ) Its suggestions should be treated as a helpful guideline rather than an infallible medical judgment, particularly for anyone managing a chronic health condition. ( ⑤ )

Because the keyboard nudges people toward its own suggestions, some linguists worry that autocomplete may be quietly narrowing everyday vocabulary. Long before a user finishes typing a sentence, the keyboard on most smartphones has already begun guessing what word comes next. ( ① ) This feature relies on a language model 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. ( ② ) The system also adapts to each individual, gradually learning a person's favorite phrases, slang, and even the names of friends that no generic dictionary would recognize. ( ③ ) This constant personalization, however, creates a subtle side effect that few users notice. ( ④ ) This small habit, choosing a convenient suggestion rather than searching for the more precise or original word one might otherwise have chosen, can add up over years of daily use. ( ⑤ )

Even small adjustments, such as dimming the lights an hour before bedtime, can make this environment noticeably more sleep-friendly. Sleep hygiene refers to a set of simple daily habits that help the body prepare for consistent, restorative rest. ( ① ) Experts commonly recommend going to bed and waking up at the same time every day, even on weekends, because an irregular schedule confuses the body's internal clock and makes it harder to fall asleep on demand. ( ② ) 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 wakeful activity rather than rest. ( ③ ) Physical environment matters as well: a cool, dark, and quiet room tends to produce deeper sleep than one that is warm, bright, or noisy. ( ④ ) 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 consistent set of cues trains an athlete's body to perform at a certain time each day. ( ⑤ )