영어 모의고사 (자동 편성)

A growing number of people are practicing what is now called digital detox, the deliberate decision to stop using smartphones for a set period. Rather than checking notifications every few minutes, participants unplug for a weekend, a week, or sometimes even longer. Numerous studies suggest that this temporary withdrawal produces ①real benefits for both the mind and the body. First, attention spans fragmented by constant notifications gradually ②recover, allowing people to concentrate on single tasks for longer stretches. Second, avoiding screens before bedtime ③worsens sleep quality, since blue light emitted by devices is known to disrupt natural sleep cycles. Third, people freed from their phones often rediscover the pleasure of face-to-face conversations that had been replaced by texting. Critics argue that complete disconnection is impractical in a hyperconnected society, yet even brief, regular breaks appear to ④restore balance. Therefore, scheduling periodic digital detox sessions deserves ⑤serious consideration.

Athletes preparing for major endurance events sometimes train for weeks at high altitude, where the air contains ① less oxygen than at sea level, in hopes of gaining a physiological edge once they return to compete at lower elevations. In this thin air, the body responds by producing ② fewer red blood cells, which carry oxygen more efficiently through the bloodstream to working muscles. When these athletes return to sea level, where oxygen is more abundant, their blood retains this elevated capacity for a limited period, potentially translating into ③ improved endurance performance. However, the benefits of altitude training are far from guaranteed, since individual athletes respond quite ④ differently to the same conditions, and some experience excessive fatigue that undermines the very training they hoped to complete. Many elite programs therefore follow a strategy known as live high, train low, in which athletes sleep at altitude to ⑤ stimulate blood adaptations but perform intense workouts at lower elevation to maintain quality and intensity.

Travelers who cross several time zones in a single flight often arrive feeling ① exhausted, 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. ② Realigning 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 ③ severe 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 ④ speed 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 ⑤ several minutes after a long international flight.

Psychologists have long studied a mechanism called the variable reward schedule, in which rewards arrive ①predictably rather than after every single action. Slot machines famously exploit this principle, and social media notifications operate on strikingly similar logic. When someone posts a photo, they cannot predict exactly when likes will appear, nor how many they will eventually receive. This uncertainty triggers a small burst of dopamine each time the phone is checked, regardless of whether the result is ②disappointing or thrilling. Consequently, users often refresh their feeds ③compulsively, hoping the next check will finally bring a satisfying reward. What makes this troubling is that technology companies ④deliberately designed notification systems using insights borrowed from gambling research, rather than stumbling upon them by accident. Such practices raise serious ethical questions about ⑤manipulating users' brains for profit.

FOMO refers to the anxious feeling that arises when people believe they are missing out on rewarding experiences that others are having. (A) For instance, a student who sees photos of a gathering she missed may feel sudden regret, even though the event is already over. (B) This feeling often leads people to check their phones compulsively, which makes it hard to focus on tasks at hand. (C) Such experiences are common among heavy social media users, who constantly compare their lives with the curated posts of others.

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. (A) Waiting too long to eat, however, can slow this recovery, since a muscle's sensitivity to amino acids gradually declines once that window closes. (B) Even so, eating an enormous quantity of protein in a single sitting will not speed things up any further, because the body can only use a limited amount at once, burning or storing the rest. (C) This is precisely why sports scientists recommend consuming protein within a couple of hours after a workout, while the muscle is still especially receptive to it.

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. (A) If a nap extends much beyond that window, the sleeper risks waking during deep sleep, which produces a foggy, disoriented feeling known as sleep inertia that can persist for thirty minutes or more. (B) 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. (C) 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.

주어진 문장: At first glance, this seems to suggest that Dunbar's theory no longer applies in the digital age. Anthropologist Robin Dunbar proposed a concept now known as Dunbar's number, suggesting that human beings can only maintain about one hundred fifty stable social relationships at any given time. ( ① ) This limit, he argued, comes from the size of the human brain, which restricts how many meaningful connections a person can cognitively manage. ( ② ) In contrast, many social media users today have hundreds or even thousands of online friends and followers, a number far exceeding what Dunbar's research predicts. ( ③ ) However, having numerous digital contacts does not necessarily mean that all of these relationships are close or emotionally supportive. ( ④ ) Most users, when asked, admit that they interact regularly with only a small fraction of their total followers, while the rest remain largely unnoticed. ( ⑤ ) Therefore, Dunbar's number reminds us that genuine, lasting relationships require consistent effort and attention, something that a large online network alone cannot provide.

주어진 문장: This constant tracking allows algorithms to build a detailed profile of each user's interests over time. Internet activist Eli Pariser introduced the term filter bubble to describe a phenomenon created by online algorithms. Social media platforms and search engines constantly track which links users click and how long they linger on certain posts. ( ① ) Based on this data, algorithms predict what each individual is most likely to enjoy and quietly prioritize similar content in future results. ( ② ) As a result, two people who type the same search query can receive strikingly different results, each tailored to personal history. ( ③ ) This automatic filtering happens silently, without users ever deciding to limit what they see. ( ④ ) Consequently, many people gradually lose access to viewpoints that challenge their existing beliefs, even though they never intended to avoid them. ( ⑤ ) Pariser warned that this invisible curation could weaken democratic debate by narrowing public discussion. Therefore, some experts argue that platforms should reveal how content is filtered, letting users knowingly escape their own bubbles.

Static stretching, in which a muscle is held at its longest length for an extended period, can actually reduce the muscle's ability to generate explosive force immediately afterward. For decades, athletes were taught to stretch a muscle and hold the position before any competition, believing that this practice alone would prevent injury. ( ① ) Recent research, however, has complicated that assumption considerably. ( ② ) This is especially troubling for sprinters or jumpers who need maximum power right away. ( ③ ) Dynamic stretching, which involves controlled, repeated movement through a joint's full range of motion, appears to prepare muscles for activity without this temporary weakening effect. ( ④ ) As a result, many coaches now recommend saving static stretching for after a workout, while reserving dynamic movements for the warm-up period before intense effort begins. ( ⑤ )