영어 모의고사 (자동 편성)

Wearable devices ①that track sleep have become enormously popular, promising a detailed breakdown of light, deep, and REM sleep each night. These gadgets typically rely on movement sensors and heart rate monitors ②to estimate sleep stages, since directly measuring brain activity would require equipment found only in a sleep laboratory. Independent studies ③compares 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 ④underestimate the amount of time spent in REM sleep, and the margin of error can vary widely between brands. Despite these limitations, many users have come ⑤to 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.

During sleep, the brain does not simply rest; it actively reorganizes the day's experiences into lasting memories through a process called consolidation. Newly formed memories are initially ①fragile and stored primarily in a brain region called the hippocampus, which has ②unlimited long-term capacity. While a person sleeps, particularly during the deep stages of non-REM sleep, neural activity replays these fresh memory traces in rapid, compressed sequences, gradually transferring the information to the cortex for more ③durable, long-term storage. This replay strengthens the connections between neurons that encoded the original experience, making the memory more ④resistant to interference from unrelated events the following day. Sleep researchers have demonstrated this effect experimentally: participants who slept after learning a list of word pairs recalled more items the next day than participants who remained awake instead. Crucially, the benefit was not limited to simple recall; sleep also seemed to help participants ⑤extract general patterns from the material, suggesting that consolidation involves more than passive storage.

Travelers who cross several time zones in a single flight often arrive feeling ①exhausted, foggy, and strangely out of sync with the local clock. The discomfort arises because the body's internal clock, which governs sleep, hunger, and alertness, continues to run on the schedule of the departure city even after landing. ②Realigning this internal clock to a new time zone is not instantaneous; researchers estimate that the body typically needs about one day to adjust for every time zone crossed. Flying eastward tends to produce more ③severe symptoms than flying westward, because advancing the internal clock forward is generally harder for the body than delaying it. Exposure to natural light at the right moments after arrival can help ④speed up the adjustment, since light is the strongest external cue the internal clock uses to reset itself. Without such adjustments, travelers may continue to experience disrupted sleep and reduced concentration for ⑤several minutes after a long international flight.

Highlighting an awkward sentence and instantly seeing three smoother alternatives has become a routine part of writing for many students, thanks to AI writing assistants built into word processors and browsers. Teachers generally welcome the grammar and spelling support, since it frees up class time to focus on argument and structure rather than comma placement. Concerns grow, however, around the tone and phrasing suggestions, which can gradually nudge every student's writing toward a similar, polished style, meaning that _______________. Some schools have begun asking students to submit an early draft alongside the final version, specifically to preserve evidence of a student's own original voice.

A short nap taken in the early afternoon, often called a power nap, can noticeably sharpen attention and mood without leaving a person groggy afterward. The key lies in timing: naps limited to roughly twenty minutes allow the brain to pass through the lightest stages of sleep while avoiding the deeper stages associated with slow-wave activity. If a nap extends much beyond that window, _______________. Laboratory studies comparing napping and non-napping groups have repeatedly shown that a brief nap improves reaction time and short-term memory almost as effectively as a full night of extra rest. Interestingly, the benefit appears strongest when the nap occurs several hours after waking, since this is when the body's natural dip in alertness makes rest most effective. For this reason, many workplaces now designate quiet rooms where employees can recharge briefly during the day.

Sleep apnea is a disorder in which breathing repeatedly stops and restarts during sleep, often because the muscles at the back of the throat relax too much and block the airway. (A) Doctors therefore rely less on a patient's own account of the night and more on objective measurements, such as overnight oxygen levels and airflow patterns recorded in a sleep laboratory. (B) Each pause can last from a few seconds to over a minute, and it may occur dozens of times in a single night without the sleeper ever waking up fully. (C) Because these interruptions rarely produce a clear memory the next morning, many people remain unaware that anything is wrong, even as chronic fatigue, headaches, and irritability build up over months.

Exercise does far more than strengthen muscles and the heart; it also produces measurable changes within the brain itself. (A) Interestingly, aerobic activities such as running or swimming appear to produce more pronounced cognitive benefits than purely strength-based training, though the precise biological reasons for this difference remain an active area of investigation. (B) Studies comparing physically active students to sedentary peers have repeatedly found that the active group performs better on tests of attention and problem-solving, even when the exercise session ends well before the test begins. (C) During sustained physical activity, the body releases a protein called brain-derived neurotrophic factor, which supports the growth of new neurons and strengthens connections between existing ones.

Modern sports wearables, from wrist-worn fitness trackers to smart insoles, continuously collect data that would once have required a laboratory to measure. (A) However, the flood of data has also created a new challenge, since distinguishing a meaningful pattern from ordinary daily fluctuation requires expertise that many amateur athletes simply do not have. (B) Coaches use this constant stream of information to detect early warning signs of overtraining, sometimes noticing a decline in performance before the athlete consciously feels tired. (C) Because of this, many teams now rely on wearable data as a routine part of daily monitoring, checking it as automatically as they once checked a stopwatch.

Skipping this final stage, even when an athlete feels fully recovered, dramatically increases the risk of re-injury, because general strength does not automatically translate into the specific coordination that a particular sport demands. Recovering from a serious sports injury involves far more than simply waiting for torn tissue to heal; it requires a carefully structured program that gradually reintroduces stress to the affected area. ( ① ) Immediately after an injury, rest and gentle range-of-motion exercises help prevent stiffness without disturbing the healing tissue. ( ② ) As pain subsides, therapists introduce light resistance training, slowly rebuilding strength in muscles that have weakened from disuse. ( ③ ) Progressing too quickly at this stage is a common mistake, since tissue that appears healed on the surface may still be structurally fragile beneath it. ( ④ ) Only after strength and flexibility approach pre-injury levels do specialists introduce sport-specific drills that mimic the exact movements an athlete will face in competition. ( ⑤ )

주어진 문장: Curious about why she always ran out of money so quickly, she asked her cousin for advice. When Mina was a freshman, she often spent her allowance within a few days. ( ① ) Her older cousin told her about the marshmallow experiment, a famous study in which children could eat one marshmallow immediately or wait for two. ( ② ) Researchers found that children who waited longer showed better academic performance and self-control years later. ( ③ ) This ability to resist an immediate reward in favor of a larger future one is known as delayed gratification. ( ④ ) Inspired by the study, Mina began saving half of her allowance each week instead of spending it all on snacks. At first, resisting small purchases felt surprisingly difficult, especially when her friends were eating out. After three months, however, she had saved enough to buy a bicycle she had wanted for over a year. ( ⑤ )