영어 모의고사 (자동 편성)

Every cell in the human body follows an internal timer known as the circadian rhythm, a roughly twenty-four-hour cycle that ① governs when we feel alert and when we feel drowsy. This clock is regulated primarily by a tiny cluster of neurons in the brain that responds to light entering through the eyes. When morning sunlight strikes the retina, the cluster signals the body to ② suppress sleep hormones and raise body temperature, preparing us for activity. As evening approaches and light fades, the same mechanism triggers the release of melatonin, a hormone that ③ promotes drowsiness. Because this rhythm evolved around the natural cycle of day and night, modern habits such as staying indoors under artificial light or working night shifts can push the internal clock ④ out of sync with the external environment. Such misalignment does not simply cause tiredness; it has also been associated with digestive problems and ⑤ heightened concentration, suggesting that timing matters as much as total sleep hours.

Behavioral economists use the term status quo bias to describe a tendency to prefer the ①**present** situation over a new alternative, even when the alternative would bring greater benefits. This bias helps explain why many households ②**rush** to switch to renewable energy, such as installing solar panels on their roofs. Although solar panels can lower electricity bills over time, homeowners often stick with their current power source because it feels ③**safe** and requires no immediate effort. In contrast, switching demands research, upfront cost, and trust in unfamiliar technology, all of which can seem ④**risky** compared with doing nothing. For example, a neighborhood association might repeatedly ⑤**postpone** a vote on shared solar panels, not because the plan is flawed, but because members are reluctant to leave their routine. Therefore, boosting renewable adoption may depend less on proving its advantages and more on designing programs that make the first step feel easy.

On a summer evening, downtown streets often feel noticeably hotter than nearby parks or suburban neighborhoods, even after the sun has set. This phenomenon, known as the urban heat island effect, occurs when _______________. Unlike soil or vegetation, which absorb and release heat gradually, these man-made surfaces absorb sunlight during the day and slowly radiate it back at night, preventing temperatures from cooling. Tall buildings packed closely together also block wind, trapping warm air within narrow streets. In contrast, areas with abundant trees and open water naturally stay cooler, since plants release moisture that helps lower surrounding temperatures. To reduce this effect, many cities have begun installing rooftop gardens and expanding public parks, hoping that additional greenery will absorb less heat than pavement does.

Have you ever noticed your mood shifting after scrolling through a friend's gloomy post online? This phenomenon, known as emotional contagion, refers to the tendency of one person's feelings to spread to others nearby, almost like a cold passing between classmates. However, researchers have discovered that emotional contagion also occurs online, where only text or images are exchanged, without any physical presence at all. For instance, when someone posts a negative comment beneath a cheerful photo, the comments that follow often turn noticeably more negative in tone. In contrast, a single kind comment can shift an entire thread toward positivity within minutes. This suggests that emotions online spread through carefully chosen words alone. Consequently, many experts now argue that ___________.

Climate scientists frequently warn about tipping points, _______________. Unlike gradual warming, which unfolds steadily over decades, crossing a tipping point can produce dramatic consequences within a short period. For instance, as Arctic ice melts, it exposes darker ocean water that absorbs more sunlight than reflective ice, accelerating further melting in a self-reinforcing cycle. Similarly, scientists worry that a major ocean current, which currently redistributes heat across the planet, could slow dramatically if enough freshwater from melting glaciers dilutes the surrounding seawater. Once such thresholds are crossed, restoring the original balance may become nearly impossible, even if emissions are later reduced. Therefore, researchers argue that preventing these transitions matters more than merely slowing average temperature increases. Identifying how close each system stands to its threshold remains one of the most urgent challenges in climate research.

Sleep is not a single, uniform state but a cycle that alternates between two very different modes: REM (rapid eye movement) sleep and non-REM sleep. (A) REM sleep, by contrast, brings rapid eye movements and brain activity resembling wakefulness, and is believed to help consolidate memories and process emotions. (B) A healthy night cycles through both stages several times, and disrupting either one can leave a person feeling unrested despite a full night in bed. (C) During non-REM sleep, particularly its deepest stage, the brain waves slow dramatically and the body focuses on physical repair.

Colors carry different psychological associations that marketers use strategically when designing logos. (A) Red, for example, often appears in logos related to food and sales, since it tends to stimulate energy and urgency. (B) Blue, on the other hand, frequently appears in logos for banks and technology companies because it suggests trust and stability. (C) These associations, however, are not universal, since the same color can carry very different meanings across cultures.

Even small adjustments, such as dimming the lights an hour before bedtime, can make this environment noticeably more sleep-friendly. Sleep hygiene refers to a set of simple daily habits that help the body prepare for consistent, restorative rest. ( ① ) 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 harder to fall asleep on demand. ( ② ) 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 to associate that space with wakeful activity rather than rest. ( ③ ) Physical environment matters as well: a cool, dark, and quiet room tends to produce deeper sleep than one that is warm, bright, or noisy. ( ④ ) 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 to perform at a certain time each day. ( ⑤ )

Yet the number displayed each morning is only as good as the estimate behind it. Wearable devices that track sleep have become enormously popular, promising a detailed breakdown of light, deep, and REM sleep each night. ( ① ) These gadgets typically rely on movement sensors and heart rate monitors to estimate sleep stages, since directly measuring brain activity would require equipment found only in a sleep laboratory. ( ② ) This indirect approach, however, introduces significant uncertainty. ( ③ ) Independent studies comparing 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. ( ④ ) Some trackers overestimate deep sleep, while others underestimate the amount of time spent in REM sleep, and the margin of error can vary widely between brands. ( ⑤ ) Despite these limitations, many users have come to 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.

주어진 문장: This is why many people find it especially difficult to maintain healthy eating habits after a long, stressful day at work. Psychologist Roy Baumeister proposed a concept called ego depletion theory, which suggests that willpower functions like a muscle that gradually tires after repeated use. ( ① ) 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. ( ② ) As this resource becomes depleted throughout the day, later decisions require more effort and are more likely to fail. ( ③ ) 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. ( ④ ) Some researchers argue that short breaks, adequate sleep, and blood sugar levels can help restore this depleted resource. ( ⑤ ) 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.