영어 모의고사 (자동 편성)

Melatonin is a hormone produced by a small gland deep within the brain, and its release follows a remarkably ①unpredictable daily pattern. Levels stay low throughout the bright hours of the day, begin rising in the evening as darkness falls, peak in the middle of the night, and then ②decline again as morning approaches. This rhythm is controlled primarily by light: specialized cells in the eye detect brightness and send signals that either permit or suppress melatonin production, which is why exposure to bright screens late at night can ③delay its release and make falling asleep more difficult. Unlike some hormones that directly cause the body to perform a task, melatonin does not force sleep to occur; instead, it signals to the rest of the body that night has arrived, preparing various systems to shift into a ④lower-energy state. Because of this signaling role, taking melatonin supplements at the wrong time can shift a person's internal clock in the ⑤opposite direction from what was intended.

Aerobic exercise, such as jogging, swimming, or cycling at a steady pace, strengthens the heart by forcing it to pump ①larger volumes of blood with each beat. Over weeks of consistent training, the heart gradually enlarges and becomes more efficient, meaning it can deliver the same amount of oxygen to working muscles while beating ②fewer times per minute. This adaptation explains why trained athletes often have a much ③lower resting heart rate than sedentary individuals of the same age. Beyond the heart itself, aerobic activity encourages the body to build new capillaries within muscle tissue, ④worsening the delivery of oxygen and nutrients at a cellular level. Researchers have also found that regular aerobic exercise ⑤reduces inflammation throughout the body and improves the way cells respond to insulin.

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.

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.

Sociologist Erving Goffman argued that people constantly perform for others, much like actors managing their image on a stage, a concept known as impression management. This idea applies vividly to social media, where users select flattering photos and delete posts that might damage their reputation. Such careful curation allows people to present an idealized version of themselves that emphasizes achievements while hiding struggles or ordinary moments. However, when this performance becomes constant, a troubling gap can form between one's authentic self and the polished character displayed online. Maintaining that gap requires considerable emotional energy, and studies suggest it often leads to anxiety and exhaustion. Furthermore, comparing one's own carefully staged life to others' equally staged posts can distort what people believe is normal. Therefore, _______________.

People rarely realize how many different roles they play throughout an ordinary day. (A) A single online post, however, reaches all of these audiences simultaneously, blending roles that were once kept apart. (B) They might act formally with a manager, casually with old friends, and gently with a younger sibling, switching tones without much thought. (C) This blending, known as context collapse, can leave posters uncertain about which version of themselves to display.

Insomnia is rarely 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) At the same time, the body's stress response system can become chronically activated, releasing hormones such as cortisol that keep heart rate and body temperature elevated at night, both of which interfere with the natural drop in arousal needed to fall asleep. (B) Poor sleep habits, including irregular bedtimes and excessive screen use before bed, can further weaken the body's internal signals for sleep onset. Because these psychological and physiological factors reinforce 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. (C) 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.

This built-in schedule does not simply respond to the clock on the wall; it is shaped directly by light itself. Every cell in the human body follows an internal timer known as the circadian rhythm, a roughly twenty-four-hour cycle that governs when we feel alert and when we feel drowsy. ( ① ) This clock is regulated primarily by a tiny cluster of neurons in the brain that responds to light entering through the eyes. ( ② ) When morning sunlight strikes the retina, the cluster signals the body to suppress sleep hormones and raise body temperature, preparing us for activity. ( ③ ) As evening approaches and light fades, the same mechanism triggers the release of melatonin, a hormone that promotes drowsiness. ( ④ ) 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 out of sync with the external environment. ( ⑤ ) Such misalignment does not simply cause tiredness; it has also been associated with digestive problems and reduced concentration, suggesting that timing matters as much as total sleep hours.

주어진 문장: In contrast, downward comparison, which involves comparing oneself with someone worse off, can temporarily boost self-esteem instead. Psychologist Leon Festinger introduced social comparison theory, which explains that people evaluate their own abilities and opinions by comparing themselves with others. ( ① ) According to this theory, individuals engage in upward comparison when they measure themselves against someone who appears more successful, attractive, or accomplished. ( ② ) Social media platforms, filled with carefully edited photos and exaggerated achievements, provide endless opportunities for this kind of comparison. ( ③ ) For instance, a teenager browsing vacation pictures posted by classmates may begin to feel that her own ordinary life is somehow inadequate. ( ④ ) Unlike comparing oneself with someone in a similar position, which can sometimes boost confidence, upward comparison frequently triggers envy, dissatisfaction, and lower self-esteem. ( ⑤ ) Researchers have found that frequent upward comparison online is linked to higher depression and anxiety. Consequently, this theory helps explain why scrolling through social media often leaves users feeling worse rather than better about themselves.

주어진 문장: Without independent verification, however, such labels can mean almost anything the company wants them to mean. Many companies today advertise their products as environmentally friendly, yet not all of these claims are accurate. ( ① ) This practice, known as greenwashing, involves exaggerating or fabricating a product's positive impact on the environment. ( ② ) Some brands print vague terms such as "natural" or "eco-conscious" on packaging without providing any evidence to support these labels. ( ③ ) Consumers, who are increasingly concerned about climate change, often trust such claims without questioning them closely. ( ④ ) As a result, they may pay higher prices for products that are no more sustainable than ordinary alternatives. ( ⑤ ) Therefore, governments should establish clear standards that require companies to prove their environmental claims with verifiable data.