영어 모의고사 (자동 편성)

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 ① most closely associated with physical restoration. REM sleep, by contrast, brings rapid eye movements, near-total muscle paralysis, and brain activity that closely ② resemble wakefulness. Most vivid dreaming occurs during this stage, and researchers believe it ③ plays a central role in consolidating memories and processing emotional experiences. A healthy night typically cycles through both stages four or five times, with non-REM ④ dominating the early hours and REM periods lengthening toward morning. Disrupting either stage, through frequent awakenings or alcohol use, can leave a person ⑤ feeling unrested even after a full night in bed.

Psychologists have long studied a mechanism called the variable reward schedule, in which rewards ①arrive unpredictably 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 ②how many they will eventually receive. This uncertainty triggers a small burst of dopamine each time the phone ③is checked, regardless of whether the result is disappointing or thrilling. Consequently, users often refresh their feeds compulsively, ④hoping the next check will finally bring a satisfying reward. What makes this troubling is that technology companies deliberately designed notification systems using insights borrowed from gambling research, rather than ⑤stumble upon them by accident.

Soyeon joined an online study group chat where dozens of students planned a class project together every evening. When one member suggested skipping a required survey step to save time, several others ①quickly agreed, and no one raised any objections. Soyeon ②privately worried that skipping the survey might weaken their project, but seeing everyone else nodding along, she stayed ③vocal rather than risk sounding difficult. The group proceeded confidently, convinced their shortcut was harmless, until their teacher pointed out ④serious gaps once the project was submitted. She realized that the chat's friendly, unified atmosphere had actually discouraged critical thinking, making poor decisions feel completely ⑤normal at the time.

Psychologists who study daily behavior describe habits through a model called the cue-routine-reward loop. This theory explains that every habit begins with a cue, a signal that tells the brain to start an automatic behavior. The brain then performs a routine, which is the action itself, whether physical or mental. Finally, the brain receives a reward, a positive feeling that makes it want to repeat the same behavior. For example, a notification sound can act as a cue that leads a student to check a phone, and the relief from boredom becomes the reward. Similarly, opening a refrigerator out of habit rather than hunger shows how a routine can run without conscious thought. Because this loop operates automatically, breaking a bad habit requires ___________. Understanding this structure helps people redesign daily patterns more effectively than relying on willpower alone.

Instead of typing keywords into a search bar, a growing number of people now simply upload a photo and let an algorithm figure out what it contains. (A) The system works by breaking an image down into countless small features, such as edges, colors, and shapes, then matching that pattern against millions of stored examples. (B) This process, known as reverse image search, compares the visual patterns in a picture against a massive database, identifying everything from a landmark in the background to the exact model of a pair of sneakers. (C) It is not flawless, however; a blurry photo, an unusual camera angle, or an object partly hidden behind another can easily confuse the algorithm.

Caffeine is the most widely consumed stimulant in the world, prized for its ability to sharpen focus and fight off fatigue within minutes of consumption. (A) For this reason, many sleep specialists advise avoiding caffeine after early afternoon, since it can quietly reduce the amount of deep, restorative sleep obtained later at night. (B) It works by blocking adenosine, a chemical that gradually builds up in the brain and makes us feel increasingly sleepy the longer we stay awake. (C) The effects, however, last far longer than most people realize, since caffeine can remain active in the bloodstream for five or six hours after it is consumed.

Not all environmental changes happen at the same steady pace. (A) A well-known example involves melting Arctic ice, which exposes darker ocean water that absorbs more sunlight and speeds up further melting in a self-reinforcing cycle. (B) Once this kind of threshold is crossed, reversing the damage becomes extremely difficult, which is why scientists consider identifying these points an urgent priority. (C) Some changes accumulate slowly and predictably, while others can suddenly accelerate once a critical threshold, known as a tipping point, is crossed.

Some changes in habit begin not with a big decision but with a quiet moment that lingers in the mind. (A) That changed when her class was assigned a documentary about plastic waste drifting through the ocean, footage she initially expected to find boring. Instead, watching seabirds mistake plastic fragments for food left her strangely unsettled, and she found herself thinking about the assignment long after class ended. (B) The next morning, almost without deciding to, she slipped her old tumbler into her backpack instead of buying a disposable cup on the way to school. It felt like a small, meaningless gesture at first. However, as weeks passed, she realized that consistently choosing the tumbler, declining a plastic straw, and reusing a shopping bag were quietly adding up. Small choices, she discovered, become meaningful once repeated. (C) Until last spring, Minji rarely thought twice about tossing a paper cup into the trash after finishing her coffee. Environmental issues seemed distant, something scientists and politicians should handle rather than an ordinary student like her.

주어진 문장: She was surprised at how little willpower this required once the routine became familiar. Minji had tried for years to build a bedtime reading habit but always forgot once under the blanket. ( ① ) During summer, she found a method called habit stacking. It means attaching a new habit to an existing one so it acts as a reminder. ( ② ) Her existing habit was brushing her teeth every night, so she decided to place her book beside her toothbrush. ( ③ ) After brushing her teeth, she would pick up the book, letting one action trigger the next. ( ④ ) Within two weeks, opening the book after brushing felt almost automatic, requiring no conscious effort. ( ⑤ ) Encouraged by this success, Minji stacked another habit onto her morning routine, reviewing vocabulary words after making her bed.

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.