영어 모의고사 (자동 편성)

When people consistently sleep too little, the body's hormonal balance shifts in ways that can quietly ① encourage weight gain. Two hormones in particular play opposing roles in regulating appetite: leptin signals fullness to the brain, while ghrelin ② stimulate the sensation of hunger. Studies show that sleep deprivation lowers leptin levels while raising ghrelin levels, so a tired body ends up ③ feeling hungrier than it actually needs to be, even after a normal-sized meal. At the same time, insufficient sleep interferes with how efficiently the body processes glucose, making cells less responsive to insulin and ④ leaving more sugar circulating in the bloodstream than usual. Over months or years, this combination of increased appetite and reduced insulin sensitivity can contribute to steady weight gain and ⑤ raise the risk of developing type 2 diabetes.

Sleep hygiene refers to a set of simple daily habits that ① helps the body prepare for consistent, restorative rest. 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 ② 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 ③ to associate that space with wakeful activity rather than rest. Physical environment matters as well: a cool, dark, and quiet room tends ④ to produce 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 consistent set of cues trains an athlete's body ⑤ to perform at a certain time each day.

Many people struggling to fall asleep in noisy environments turn to white noise machines, devices that emit a steady, uniform sound covering a broad range of frequencies. The appeal lies in a phenomenon called auditory masking, in which a constant background sound makes sudden noises less noticeable to the sleeping brain. Without this masking effect, _______________. Studies comparing sleep in quiet rooms with sleep alongside white noise have found that participants using white noise experienced fewer of these brief awakenings and reported feeling more rested.

Psychologist Roy Baumeister proposed a concept called ego depletion theory, which suggests that ___________. According to this theory, every act of self-control, from resisting a snack to concentrating on difficult homework, draws from the same limited mental resource. As this resource becomes depleted throughout the day, later decisions require more effort and are more likely to fail. For instance, someone who exercises discipline avoiding distractions all morning may struggle to resist checking a phone by evening. Likewise, dieters report that self-control weakens sharply at night, after hours of resisting food. Some researchers argue that short breaks, adequate sleep, and blood sugar levels can help restore this depleted resource. Although later studies have questioned how strong this effect is, the theory still offers a useful framework for understanding why willpower seems to fade throughout a long day.

Across many countries, high schools begin classes early in the morning, often before eight o'clock. This schedule assumes that teenagers can simply go to bed earlier to compensate, but biology tells a different story. During adolescence, the body's internal clock shifts later, delaying the release of melatonin until well after ten at night. As a result, most teenagers are not physiologically ready to fall asleep until much later than younger children or adults. When early start times force them to wake before their bodies have completed a full sleep cycle, the mismatch accumulates into a chronic sleep debt that affects concentration and mood throughout the school day. Researchers who study this mismatch argue that _______________. Some school districts that delayed their start times by thirty minutes reported improvements in attendance, suggesting that the timing of the school day matters more than commonly assumed.

Many people who try digital detox for the first time report feeling anxious within the first few hours. (A) This initial discomfort, sometimes called withdrawal anxiety, tends to fade after a day or two as the mind adjusts to reduced stimulation. (B) Once that adjustment period passes, most participants describe a noticeable sense of calm that they had not expected. (C) This unexpected calm often motivates people to repeat the practice regularly instead of treating it as a one-time experiment.

Melatonin is a hormone produced by a small gland deep within the brain, and its release follows a remarkably predictable daily pattern. (A) This rhythm is controlled primarily by light: specialized cells in the eye detect brightness and send signals that either permit or suppress melatonin production, which is why exposure to bright screens late at night can delay its release and make falling asleep more difficult. (B) Levels stay low throughout the bright hours of the day, begin rising in the evening as darkness falls, peak in the middle of the night, and then decline again as morning approaches. (C) 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, 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 intended.

주어진 문장: Interestingly, this principle was first observed in government offices, where paperwork seemed to multiply regardless of actual workload. Time-management researchers frequently mention a principle known as Parkinson's Law, which states that work expands to fill the time available for its completion. ( ① ) According to this idea, a task that could be finished in one hour will often stretch to fill an entire afternoon if that much time is scheduled for it. ( ② ) Students who set vague deadlines frequently experience this effect, spending extra hours refining a report that was already complete. ( ③ ) Employees given a full week for a simple project may also delay meaningful progress until the final days, even though the actual work requires far less effort. ( ④ ) This pattern happens partly because people unconsciously adjust their pace to match perceived urgency. ( ⑤ ) Setting shorter, more specific deadlines can counter this tendency, forcing tasks to fit within a tighter and more realistic window. By recognizing how flexible time encourages unnecessary delay, individuals can complete assignments more efficiently without sacrificing quality.

Athletes competing in hot, humid conditions face a particularly difficult balance, because sweating heavily to stay cool simultaneously depletes the very fluids needed to sustain performance. Even a modest level of dehydration, as little as two percent of body weight lost through sweat, can measurably reduce an athlete's endurance and cognitive sharpness during competition. ( ① ) As fluid levels drop, blood volume decreases, forcing the heart to work harder to deliver the same amount of oxygen to working muscles, which accelerates fatigue. ( ② ) Dehydration also impairs the body's ability to regulate its own temperature, since sweating is the primary mechanism for releasing excess heat during intense exercise. ( ③ ) Simply drinking large amounts of plain water is not always sufficient, however, since heavy sweating also flushes out sodium and other electrolytes essential for proper muscle function. ( ④ ) For this reason, sports scientists generally recommend a hydration strategy that replaces both fluid and electrolytes, tailored to an individual athlete's sweat rate and the specific conditions of the event. ( ⑤ )

주어진 문장: This explains why progress often feels rapid and motivating during the earliest days of learning something new. The twenty-hour rule proposes that years of practice are not needed to become skilled at a new activity. ( ① ) Only about twenty hours of effort are needed to reach a useful level. Unlike theories claiming true mastery requires ten thousand hours, this rule targets a more modest goal. That goal is simple competence for everyday use. ( ② ) According to supporters, practicing any new skill produces the fastest visible improvement, since a beginner has room to grow. ( ③ ) Someone learning guitar can typically strum simple chords and follow a basic song within twenty hours of daily practice. ( ④ ) Likewise, a language learner may soon order food or ask directions without years of formal study. ( ⑤ ) Advocates emphasize that the twenty hours must be deliberate and focused, broken into short daily sessions rather than one long stretch. The hours should be aimed at fixing weaknesses rather than repeating what one already knows.