영어 모의고사 (자동 편성)

Exercise does far more than strengthen muscles and the heart; it also produces measurable changes within the brain itself. During sustained physical activity, the body ① releases a protein called brain-derived neurotrophic factor, which supports the growth of new neurons and ② strengthens connections between existing ones, particularly in regions associated with memory and learning. Studies comparing physically active students to sedentary peers have repeatedly found that the active group ③ performing better on tests of attention and problem-solving, even when the exercise session ends well before the test begins. Researchers believe that exercise increases blood flow to the brain, ④ delivering oxygen and nutrients more efficiently, while also reducing levels of stress hormones that can interfere with clear thinking. These findings have encouraged some schools ⑤ to schedule exercise before demanding academic classes.

Years ago, a small shoe company struggled to compete with larger, well-funded rivals in the market. Its products were ①solid, but customers rarely ②remembered the brand after a single purchase. Sales slowly ③decreased as people felt they were supporting something meaningful rather than simply buying a product. Other companies noticed this shift and began crafting their own narratives, hoping to create similar ④emotional connections. Eventually, the founder realized that a compelling story, told honestly, could turn ordinary customers into ⑤loyal supporters.

Even a modest level of dehydration, as little as two percent of body weight lost through sweat, can measurably reduce an athlete's endurance and cognitive sharpness during competition. As fluid levels drop, blood volume decreases, forcing the heart to work harder to deliver the same amount of oxygen to working muscles, which accelerates fatigue. Athletes competing in hot, humid conditions face a particularly difficult balance, because sweating heavily to stay cool simultaneously depletes the very fluids needed to sustain performance. Simply drinking large amounts of plain water is not always sufficient, however, since _______________. For this reason, sports scientists generally recommend a hydration strategy that replaces both fluid and electrolytes.

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.

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.

주어진 문장: Yet this same tendency also carries a hidden drawback. Sociologists use the term homophily to describe the tendency of people to form connections with others who share similar backgrounds, opinions, or interests. ( ① ) This principle explains why classmates from the same major often become close friends, while coworkers with shared hobbies naturally gravitate toward one another. ( ② ) Because similarity reduces the effort required to understand another person's perspective, relationships built on shared traits tend to feel comfortable and require less negotiation. ( ③ ) However, this same comfort can narrow the range of viewpoints someone encounters, since surrounding oneself with similar people limits exposure to different ideas. ( ④ ) Social media platforms intensify this pattern through recommendation algorithms that suggest new friends based on shared interests or similar browsing history. ( ⑤ ) As a result, users often find their online circles becoming increasingly homogeneous, filled with people who think and behave much like themselves.

주어진 문장: In reality, however, that "original" price was sometimes never actually charged to any customer. Retailers frequently rely on sales events to boost short-term revenue, but the psychology behind these promotions is more complex than simple discounting. ( ① ) When a price is crossed out and replaced with a lower number, consumers instinctively perceive the new price as a bargain. ( ② ) This technique, known as anchoring, shapes how shoppers judge value by comparing prices rather than evaluating a product on its own merits. ( ③ ) Limited-time sales further intensify this effect, since a ticking clock encourages rushed decisions that leave little room for careful comparison. ( ④ ) Retailers also use phrases such as "while supplies last" to suggest scarcity, even when inventory remains plentiful. ( ⑤ ) Over time, frequent sales can actually train customers to wait for discounts rather than buy at full price.

주어진 문장: Not every transaction goes smoothly, however, since photographs and descriptions cannot always capture an item's true condition. Secondhand trading platforms, once considered a niche market for used goods, have grown into a mainstream part of consumer culture. ( ① ) Rising prices for new products, combined with growing awareness of environmental waste, have encouraged many shoppers to consider used items before purchasing something brand new. ( ② ) These platforms allow individuals to sell clothing, electronics, and furniture directly to other consumers, cutting out traditional retail markups entirely. ( ③ ) For younger buyers especially, purchasing secondhand items has become associated with resourcefulness rather than financial necessity. ( ④ ) Sellers benefit as well, earning extra income from items that would otherwise sit unused in storage. ( ⑤ ) To address this problem, many platforms now offer buyer protection programs and detailed rating systems for sellers.

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.

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