영어 모의고사 (자동 편성)

A short nap taken in the early afternoon, often called a power nap, can noticeably sharpen attention and mood without ① leaving a person groggy afterward. The key lies in timing: naps limited to roughly twenty minutes allow the brain ② 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, the sleeper risks ③ waking during deep sleep, which produces a foggy, disoriented feeling known as sleep inertia that can persist for thirty minutes or more. Laboratory studies ④ 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 ⑤ effectively.

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.

After a strenuous workout, muscle fibers experience thousands of microscopic tears, and the body immediately begins a repair process that depends heavily on amino acids, the building blocks that protein supplies. This is why sports scientists recommend consuming protein within a couple of hours after training, since _______________. Many athletes assume that eating an enormous quantity of protein in a single sitting will speed up this process, but the body can only use a limited amount at once; the rest is simply burned for energy or stored as fat.

Sociologist Mark Granovetter introduced an idea that seems contradictory at first glance, known as the strength of weak ties. According to this theory, people who see each other only occasionally, called weak ties, often provide more valuable information than close friends or family members, who are considered strong ties. This happens because strong ties tend to share the same social circles and, therefore, already possess similar knowledge. Weak ties, in contrast, move within different networks, which allows them to introduce ideas or opportunities that would otherwise remain unknown. For example, a former classmate rarely contacted might mention a job opening unavailable through one's immediate circle. Social media platforms have made maintaining such connections remarkably easier, letting users keep hundreds of loose acquaintances active without frequent face-to-face meetings. Consequently, these platforms _______________.

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.

The growing sophistication of cyberattacks has transformed cybersecurity into one of the most in-demand career fields. (A) Universities have responded to this trend by launching specialized degree programs focused entirely on cybersecurity. (B) As a result, businesses across nearly every industry now compete to hire qualified security professionals. (C) Hackers today target organizations of every size, from small retailers to major financial institutions.

Smart speakers have quietly become a fixture in many households, responding to spoken requests for weather updates, music, or kitchen timers. (A) Still, the technology remains far from perfect, since background noise, overlapping voices, or an unusual sentence structure can cause the assistant to misunderstand a simple request. (B) Because these assistants improve by learning from millions of interactions, they gradually become better at recognizing regional accents and casual phrasing that once confused them. (C) Behind this simple exchange lies a complex process: the device converts sound waves into text, interprets the meaning, and then generates a spoken reply, all within a second or two.

Long before social media existed, people naturally clustered into groups based on shared traits. (A) These algorithms track patterns such as shared interests, mutual friends, and browsing habits to recommend new connections. (B) Neighborhoods, schools, and workplaces often reflected this tendency, as individuals gravitated toward others who resembled themselves. (C) Today, however, this same tendency operates through recommendation algorithms built into social media platforms.

When the body fights off an infection, the immune system relies heavily on adequate sleep to function effectively. (A) Rather than being a passive state in which the body simply rests, sleep functions as an active period during which the immune system repairs itself and prepares for future threats, which is why doctors often recommend extra sleep when someone is fighting an illness. (B) Chronic sleep deprivation also appears to promote low-grade inflammation throughout the body, a state that has been linked to a higher risk of heart disease and other chronic conditions. (C) During deep sleep, the body produces and releases cytokines, proteins that help regulate immune responses, and people who consistently sleep fewer than six hours a night show measurably weaker antibody responses after vaccination.

In other words, sleep does not simply preserve what was learned but actively works to make sense of it. During sleep, the brain does not simply rest; it actively reorganizes the day's experiences into lasting memories through a process called consolidation. ( ① ) Newly formed memories are initially fragile and stored primarily in a brain region called the hippocampus, which has limited long-term capacity. ( ② ) 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 durable, long-term storage. This replay strengthens the connections between neurons that encoded the original experience, making the memory more resistant to interference from unrelated events the following day. ( ③ ) 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. ( ④ ) Crucially, the benefit was not limited to simple recall; sleep also seemed to help participants extract general patterns from the material, suggesting that consolidation involves more than passive storage. ( ⑤ )