영어 모의고사 (자동 편성)

For centuries, dreams have fascinated scientists and philosophers alike, yet no single theory fully ①explains why the sleeping brain generates such vivid and often bizarre experiences. One prominent idea suggests that dreaming helps the brain process emotional experiences, ②replays difficult events in a safe, low-stakes environment so that their emotional intensity gradually fades. Another theory proposes that dreams serve a more practical function, ③allowing the brain to rehearse responses to threats without any real danger. Still other researchers argue that dreaming is simply a byproduct of the brain organizing memories, with vivid imagery ④arising as the mind sorts through the day's information rather than serving any independent purpose of its own. Because these theories rest on indirect evidence, none has ⑤been conclusively proven.

Caffeine is the most widely consumed stimulant in the world, prized for its ability to ①sharpen focus and fight off fatigue within minutes of consumption. It works by blocking adenosine, a chemical that gradually builds up in the brain throughout the day and makes us feel ②decreasingly sleepy the longer we stay awake. By occupying the receptors that adenosine would normally bind to, caffeine tricks the brain into feeling alert even when the body has accumulated significant sleep pressure. The effects, however, last far longer than most people realize. Because caffeine can remain active in the bloodstream for five to six hours, a cup of coffee consumed in the late afternoon may still be ③interfering with the ability to fall asleep at midnight. Even when people do not consciously notice difficulty falling asleep, caffeine has been shown to ④reduce the amount of deep, restorative sleep obtained later in the night. For this reason, many sleep specialists advise ⑤avoiding caffeine after early afternoon.

Insomnia is ①rarely caused by a single factor; it usually emerges from an interaction between psychological stress and physiological arousal that keeps the body from settling into sleep. A common trigger is what researchers call cognitive hyperarousal, in which the mind continues to race with worries about work, relationships, or even the inability to sleep itself, creating a frustrating cycle where anxiety about insomnia becomes a cause of insomnia. At the same time, the body's stress response system can become ②chronically activated, releasing hormones such as cortisol that keep heart rate and body temperature ③depressed at night, both of which interfere with the natural drop in arousal needed to fall asleep. Poor sleep habits, including irregular bedtimes and excessive screen use before bed, can further ④weaken the body's internal signals for sleep onset. Because these psychological and physiological factors ⑤reinforce one another, effective treatment for chronic insomnia addresses both the racing mind and the underlying pattern of physical tension, rather than relying on medication alone.

Minji spent nearly every evening watching Jimin, an online creator who streamed cooking videos and chatted casually with her viewers. Over several months, Minji began to feel as though she truly knew Jimin, ①laughing at her jokes and worrying whenever she mentioned having a difficult week. Whenever Jimin responded to a comment, even a simple one, Minji felt a small thrill of connection, as if they were becoming closer friends. One day, Minji ②reluctantly waited outside a fan event, hoping that Jimin would ③recognize her from the countless messages she had sent. However, Jimin greeted her the same way she greeted every other stranger in line, without any hint of personal recognition. Standing there, Minji slowly realized that the bond she had imagined was entirely ④one-sided, existing only in her own mind. This type of connection, known as a parasocial relationship, can feel remarkably ⑤real despite never being mutual.

Psychologist Leon Festinger introduced social comparison theory, which explains that people ①evaluate their own abilities and opinions by comparing themselves with others. According to this theory, individuals engage in upward comparison when they measure themselves against someone who appears more ②successful, attractive, or accomplished. For instance, a teenager browsing vacation pictures posted by classmates may begin to feel that her own ordinary life is somehow ③inadequate. Unlike comparing oneself with someone in a similar position, which can sometimes ④boost confidence, upward comparison frequently triggers envy, dissatisfaction, and lower self-esteem. Researchers have found that frequent upward comparison online is linked to ⑤lower depression and anxiety.

Many people feel a sudden wave of anxiety when their smartphone battery is nearly dead or they have left it at home. This intense discomfort, known as nomophobia, is short for "no-mobile-phone phobia," a term describing the fear of losing connection to one's phone. Nomophobia involves physical symptoms, including a racing heart, sweating, and restlessness, whenever a person cannot check messages or social media. Researchers explain that this fear develops because smartphones have become tightly linked to social belonging; missing a notification can feel like being cut off from friends. For example, some students check their phones dozens of times an hour, even during class, just to confirm nothing important has been missed. Therefore, experts suggest gradually reducing phone checks to weaken this anxious dependence. ___________.

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. During non-REM sleep, especially its deepest stage, the brain waves slow down dramatically, the body temperature drops, and tissue repair and growth hormone release reach their peak. This is the period most closely associated with physical restoration. REM sleep, by contrast, brings rapid eye movements, near-total muscle paralysis, and brain activity that closely resembles wakefulness. Most vivid dreaming occurs during this stage, and researchers believe _______________. A healthy night typically cycles through both stages four or five times, with non-REM dominating the early hours and REM periods lengthening toward morning. Disrupting either stage, through frequent awakenings or alcohol use, can leave a person feeling unrested even after a full night in bed.

Generation Z is reshaping consumer culture in ways that surprise many traditional marketers. (A) As a result, brands that rely solely on flashy advertising campaigns often struggle to win their loyalty. (B) They tend to research thoroughly before buying and expect companies to demonstrate genuine values, not just attractive slogans. (C) Instead, this generation responds more strongly to transparency and honest communication from the brands they support.

This happens because the eyes remain remarkably responsive to light even after darkness falls, cueing the brain that it is still daytime. Smartphones, tablets, and computer screens all emit a significant amount of blue light, a short-wavelength light that our eyes are especially sensitive to. ( ① ) During the day, exposure to blue light from the sun helps keep us alert and mentally sharp, which is generally beneficial. ( ② ) At night, however, the same wavelength can interfere with the body's natural preparation for sleep. ( ③ ) Specialized cells in the retina detect blue light and send signals to the brain's internal clock, suppressing the release of melatonin, the hormone that signals it is time to rest. ( ④ ) Studies have found that people who scroll through their phones in bed before sleeping take longer to fall asleep and experience lighter, more easily disrupted sleep than those who avoid screens. ( ⑤ ) Some devices now offer a night mode that shifts the display toward warmer tones, reducing blue light output in the evening. While this feature may help slightly, sleep researchers generally recommend limiting screen use altogether in the hour before bedtime for the best results.

Even a modest weight gain caused by these hormonal shifts can, over time, make the body's cells even less sensitive to insulin, creating a cycle that is hard to break. When people consistently sleep too little, the body's hormonal balance shifts in ways that can quietly encourage weight gain. ( ① ) Two hormones in particular play opposing roles in regulating appetite: leptin signals fullness to the brain, while ghrelin stimulates the sensation of hunger. ( ② ) Studies show that sleep deprivation lowers leptin levels while raising ghrelin levels, so a tired body ends up feeling hungrier than it actually needs to be, even after a normal-sized meal. ( ③ ) At the same time, insufficient sleep interferes with how efficiently the body processes glucose, making cells less responsive to insulin and leaving more sugar circulating in the bloodstream than usual. ( ④ ) Over months or years, this combination of increased appetite and reduced insulin sensitivity can contribute to steady weight gain and raise the risk of developing type 2 diabetes. ( ⑤ ) Because these effects build up so gradually, many people never connect their shifting eating habits or worsening blood sugar to something as ordinary as a few lost hours of sleep each night.