영어 모의고사 (자동 편성)

In the days leading up to an endurance event, many athletes deliberately increase their carbohydrate intake while reducing training volume, a practice ①known as carbohydrate loading. The strategy ②is design to maximize the amount of glycogen, the storage form of carbohydrate, packed into muscle tissue before competition begins. Because glycogen serves as the primary fuel source during prolonged, intense exercise, entering an event with fuller stores can delay the point of exhaustion that runners often ③call hitting the wall. Sports nutritionists caution, however, that the timing and composition of meals ④matter as much as the total quantity of carbohydrate consumed, since eating unfamiliar foods immediately before competition can cause digestive discomfort. Athletes are therefore advised ⑤to practice their nutrition strategy during training rather than experimenting with it for the first time on race day.

Consider a village green shared freely by every herder in the community, where each individual may graze as many animals as they wish without ①paying any fee. From the perspective of any single herder, adding one more animal to the shared pasture ②brings a clear personal benefit, since the extra income belongs entirely to that herder alone. The cost of the additional grazing, however, is spread thinly across every herder who uses the green, so no single individual ③bears more than a tiny fraction of the damage. Because this calculation favors adding more animals for every rational herder, the shared pasture is gradually overgrazed until it can no longer ④support any animals at all, harming the very community whose rational members caused the collapse. Philosophers use this scenario to illustrate a troubling gap between what benefits an individual in the short term and what preserves a shared resource in the long term, a gap that voluntary self-restraint alone rarely ⑤closing.

Highlighting an awkward sentence and instantly seeing three smoother alternatives has become a routine part of writing for many students, thanks to AI writing assistants ①built into word processors and browsers. These tools check grammar and spelling, of course, but the more advanced versions go further, ②suggesting clearer phrasing, flagging repetitive words, and even adjusting tone to sound more formal or more casual depending on the purpose. Teachers generally welcome the grammar and spelling support, since it ③frees up class time to focus on argument and structure rather than comma placement. Concerns grow, however, around the tone and phrasing suggestions, which can gradually ④nudge every student's writing toward a similar, polished style. Some schools have begun asking students ⑤submit an early draft alongside the final version, specifically to preserve evidence of a student's own original voice.

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.

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

Before making a purchase, most online shoppers now read reviews written by previous customers rather than relying solely on advertisements. These reviews, posted by people who have no financial connection to the seller, often seem more trustworthy than promotional claims. Research shows that products with a large number of positive reviews sell significantly more than those with few or no reviews at all. However, fake reviews written by paid writers or even automated programs have become a serious problem, undermining consumer trust. Platforms that fail to detect these fraudulent posts risk losing credibility with their users, who expect authentic opinions when making decisions. To address this issue, several review platforms have begun using artificial intelligence to identify suspicious patterns. Ultimately, the power of online reviews ___________.

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 releases a protein called brain-derived neurotrophic factor, which supports the growth of new neurons and 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 _______________, even when the exercise session ends well before the test begins. Researchers believe that exercise increases blood flow to the brain, delivering oxygen and nutrients more efficiently, while also reducing levels of stress hormones that can interfere with clear thinking.

Elite athletes rarely walk up to a free throw line or a golf ball without first performing a highly specific sequence of movements, a habit sports psychologists call a pre-performance routine. (A) Researchers have found that athletes who follow a consistent routine tend to show more stable performance under pressure than those who approach each attempt differently. (B) Far from being mere superstition, this consistent sequence serves a genuine cognitive purpose, narrowing an athlete's focus away from distracting thoughts and toward the specific technical cues needed to execute the skill correctly. (C) For this reason, coaches now actively teach young athletes to develop and rehearse individualized routines rather than treating them as personal quirks.

Every day, email providers quietly block billions of unwanted messages before they ever reach a user's inbox, a task that would be impossible without an AI filtering system running constantly in the background. (A) This creates a constant back-and-forth, since spammers study which messages get blocked and then adjust their wording to slip through again. (B) The filter examines each incoming message for suspicious patterns, including certain keywords, unusual sender addresses, and formatting tricks that scammers commonly rely on to slip past detection. (C) What makes the system effective is that it keeps learning after launch, since a user's action of marking or rescuing a message becomes new training data.

This gap remains even after accounting for factors such as study habits, motivation, and overall intelligence. Researchers who study teenagers have found a strong link between how well students sleep and how well they perform in school. ( ① ) Students who sleep fewer than seven hours a night tend to score lower on tests of memory and attention than those who sleep eight or nine hours, even when the two groups study for the same number of hours. ( ② ) One explanation is that sleep plays an active role in learning: during certain stages of sleep, the brain replays and strengthens information encountered during the day, converting fragile short-term memories into more durable long-term ones. ( ③ ) When sleep is cut short, this consolidation process is interrupted before it can finish, so material that seemed well understood the night before often feels unfamiliar the next morning. ( ④ ) For this reason, some schools have begun rethinking early start times, reasoning that an extra hour of sleep might do more for test scores than an extra hour of studying ever could. ( ⑤ )