영어 모의고사 (자동 편성)

Researchers who ① study teenagers have found a strong link between how well students sleep and how well they perform in school. Students who sleep fewer than seven hours a night tend to score lower on tests of memory and attention than those who ② sleep eight or nine hours, even when the two groups study for the same number of hours. One explanation is that sleep plays an active role in learning: during certain stages of sleep, the brain replays and strengthens information ③ encountered during the day, converting fragile short-term memories into more durable long-term ones. When sleep is cut short, this consolidation process is interrupted before it can finish, so material that seemed well understood the night before often ④ feel unfamiliar the next morning. For this reason, some schools have begun rethinking early start times, reasoning that an extra hour of sleep might do more for test scores than an extra hour of studying ever ⑤ could.

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. 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 ① waking up fully. Because these interruptions rarely produce a clear memory the next morning, many people remain ② unaware that anything is wrong, even as chronic fatigue, headaches, and irritability build up over months. 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 ③ recording in a sleep laboratory. ④ Left untreated, the disorder has been linked to serious long-term risks, including high blood pressure and heart disease, which makes an accurate diagnosis far more urgent than its subtle nighttime symptoms might ⑤ suggest.

Ambitious young athletes and the parents who support them sometimes assume that more training automatically produces ① better results, a belief that occasionally leads to a condition known as overtraining syndrome. Unlike ordinary fatigue that resolves after a few days of rest, overtraining syndrome develops ② rapidly within a single day of insufficient recovery, eventually producing persistent exhaustion, declining performance despite continued hard work, and increased susceptibility to illness and injury. Adolescents may be especially vulnerable, since their bodies are simultaneously coping with the physical demands of growth and the added stress of intensive training schedules. Warning signs are often ③ subtle at first, including disrupted sleep, irritability, and a loss of enthusiasm for a sport the athlete once genuinely enjoyed. Recovery from full-blown overtraining syndrome can take ④ months rather than days, which is why sports medicine specialists now emphasize monitoring early warning signs and scheduling rest before symptoms ⑤ worsen.

Consider a large heap containing ten thousand grains of sand. Nearly everyone agrees that removing a single grain from such a heap leaves another heap behind; surely one grain could never make the difference between a heap and a non-heap. Yet if this principle is applied repeatedly, grain by grain, the heap eventually shrinks to a single lonely grain, or even to no grains at all, and logic alone seems to force us to accept that this final result still counts as a heap. Something has clearly gone wrong along the way, since no reasonable person would call one grain of sand a heap, but pinpointing exactly which single removal transformed a heap into a non-heap seems impossible. The puzzle exposes a deep discomfort with vague terms like "heap," "tall," or "bald," concepts that seem to admit no sharp boundary yet are used confidently in everyday language. Some philosophers conclude that _______________.

Scientists have identified certain gene variants that appear more frequently among elite endurance athletes than among the general population, along with a separate set that seems to favor explosive, power-based sports such as sprinting. One frequently studied variant, for instance, influences the proportion of slow-twitch versus fast-twitch muscle fibers a person naturally develops, a ratio that shapes whether a body leans toward endurance or explosive power. However, researchers caution strongly against interpreting these findings as evidence that athletic greatness is simply inherited, since _______________. Genetics may set a rough ceiling on an individual's ultimate potential, but where any particular athlete lands within that range depends overwhelmingly on training quality, nutrition, coaching, and sheer determination.

Economists traditionally measured a community's wealth in terms of factories, income, or infrastructure, yet sociologists increasingly point to a less visible resource: social capital, the networks of trust and reciprocity that allow people to cooperate for mutual benefit. Robert Putnam popularized the concept by documenting a decline in civic participation, a trend he captured in the phrase bowling alone. Communities rich in social capital tend to enjoy lower crime and more effective local government, because neighbors who know and trust one another can coordinate informally without relying entirely on formal institutions. However, _______________. For this reason, researchers increasingly distinguish between bonding capital, which strengthens ties within a single group, and bridging capital, which connects otherwise separate communities.

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. (A) Sports scientists note an important caveat, however: a wrist-based sensor cannot fully capture the same physiological detail available in a professional lab. (B) 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. (C) Amateur athletes often credit this kind of guidance with helping them train more consistently without pushing their bodies too hard.

Coaches have traditionally focused athlete preparation on training volume and nutrition, but a growing body of research suggests that sleep deserves equal attention. (A) In response, many professional teams now employ sleep specialists who design travel schedules, control bedroom lighting and temperature, and even adjust competition start times when possible. (B) Frequent travel across time zones compounds this challenge considerably, since jet lag can disrupt an athlete's natural sleep-wake cycle for several days after a long flight. (C) During deep sleep, the body releases growth hormone, essential for repairing muscle tissue, while the brain consolidates motor skills practiced earlier that day into more stable, efficient patterns.

In other words, no single app may intend to expose such sensitive information, but the combination of many small pieces can. Every time a smartphone connects to a cell tower or a Wi-Fi network, it quietly records a data point that can later be pieced together into a detailed map of where its owner has been. ( ① ) Most users agree to this tracking without reading the fine print, assuming that a single company's database poses little threat. ( ② ) The real danger, however, emerges when location data from multiple sources is combined. ( ③ ) A pattern that reveals a person's home, workplace, and daily route can expose far more than any single app ever intended to share, including medical visits or private relationships. ( ④ ) Companies often argue that anonymized data cannot be traced back to individuals, yet researchers have repeatedly shown otherwise. ( ⑤ )

This process, though it may sound simple, triggers a remarkable series of adaptations throughout the cardiovascular system. Aerobic exercise, such as jogging, swimming, or cycling at a steady pace, strengthens the heart by forcing it to pump larger volumes of blood with each beat. ( ① ) Over weeks of consistent training, the heart gradually enlarges and becomes more efficient, meaning it can deliver the same amount of oxygen to working muscles while beating fewer times per minute. ( ② ) This adaptation explains why trained athletes often have a much lower resting heart rate than sedentary individuals of the same age. ( ③ ) Beyond the heart itself, aerobic activity encourages the body to build new capillaries within muscle tissue, improving the delivery of oxygen and nutrients at a cellular level. ( ④ ) Researchers have also found that regular aerobic exercise reduces inflammation throughout the body and improves the way cells respond to insulin. ( ⑤ )