영어 모의고사 (자동 편성)

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

Melatonin is a hormone ① produced by a small gland deep within the brain, and its release follows a remarkably predictable daily pattern. Levels stay low throughout the bright hours of the day, ② begin rising in the evening as darkness falls, peak in the middle of the night, and then decline 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 ③ suppress melatonin production, which is why exposure to bright screens late at night can delay 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, ④ preparing various systems to shift into a lower-energy state. Because of this signaling role, taking melatonin supplements at the wrong time can shift a person's internal clock in the opposite direction from what was ⑤ intending.

For decades, athletes were taught to stretch a muscle and hold the position before any competition, believing that this practice alone would ① prevent injury. Recent research, however, has complicated that assumption considerably. Static stretching, in which a muscle is held at its longest length for an extended period, can actually ② reduce the muscle's ability to generate explosive force immediately afterward, which is troubling for sprinters or jumpers who need maximum power right away. Dynamic stretching, which involves controlled, repeated movement through a joint's full range of motion, appears to ③ prepare muscles for activity without this temporary weakening effect. As a result, many coaches now recommend ④ saving static stretching for after a workout, when it may help restore muscle length and reduce soreness, while reserving dynamic movements for the warm-up period before intense effort begins. The right technique, in other words, depends heavily on ⑤ chance.

Feed an AI music program a mood, a tempo, and a rough genre, and within seconds it can generate a complete instrumental track, ready to be dropped under a video or used as background music for a small business. The software has studied thousands of existing songs, learning which chord progressions and rhythms tend to sound ① pleasant together, and it ② recombines these patterns into something new rather than copying any single source directly. For independent creators who cannot afford a composer or expensive licensing fees, this has been a genuine ③ breakthrough. Professional musicians, however, remain divided. Some welcome the tool as a quick way to sketch ideas before refining them by hand, while others ④ celebrate that a flood of AI-generated background music could quietly push human composers out of smaller, lower-budget projects. ⑤ the very jobs many musicians once relied on to build a career.

Long before a user finishes typing a sentence, the keyboard on most smartphones has already begun guessing what word comes next. This feature relies on a language model trained to notice which words commonly follow one another, so it can offer a shortlist of likely candidates above the keyboard, ① saving users countless keystrokes over the course of a day. The system also adapts to each individual, gradually learning a person's favorite phrases, slang, and even the names of friends that no generic dictionary would ② recognize. This constant personalization, however, creates a subtle side effect that few users notice. Because the keyboard ③ nudges people toward its own suggestions, some linguists worry that autocomplete may be quietly ④ widening everyday vocabulary, encouraging writers to accept a convenient suggestion rather than searching for the more precise or original word they might otherwise have ⑤ chosen.

Planning a multi-city trip once meant hours spent comparing flight schedules, reading hotel reviews, and mapping out which sights were close enough to visit in a single day. AI travel planners now ① compress much of that work into a short conversation, asking about a budget, a travel style, and a handful of preferences before generating a full day-by-day itinerary within minutes. The tool draws on enormous amounts of data to suggest a route that avoids obvious ② scheduling conflicts. Many travelers appreciate having a solid starting point rather than a ③ blank page. Still, seasoned travelers warn that these itineraries can feel oddly ④ unique, often steering users toward the same popular landmarks that every other AI-generated plan recommends, while ⑤ overlooking smaller, lesser-known places that a knowledgeable local guide might have suggested instead.

Open a music streaming app on any given morning, and a personalized playlist is usually already waiting, assembled overnight from songs the algorithm predicts will match a listener's current mood. Listeners often praise the feature for introducing them to artists they never would have searched for on their own. Musicians, meanwhile, have mixed feelings about this shift in how audiences discover new music. A song that the algorithm decides not to promote may struggle to reach listeners no matter how well it was written, meaning that _______________.

Travelers who cross several time zones in a single flight often arrive feeling exhausted, foggy, and strangely out of sync with the local clock, a condition widely known as jet lag. The discomfort arises because the body's internal clock continues to run on the schedule of the departure city even after landing. Realigning this internal clock to a new time zone is not instantaneous; researchers estimate that the body typically needs about one day to adjust for every time zone crossed. Flying eastward tends to produce more severe symptoms than flying westward, because _______________. Exposure to natural light at the right moments after arrival can help speed up the adjustment, since light is the strongest external cue the internal clock uses to reset itself.

When a customer opens a company's website at midnight with a billing question, an actual employee is unlikely to be available, which is exactly the gap that customer service chatbots were built to fill. (A) These programs can instantly answer common questions, track packages, and process simple refunds without making anyone wait on hold, and a single chatbot can handle thousands of conversations simultaneously. (B) Yet the technology has clear boundaries, since an unusual or emotionally charged problem can leave the automated replies feeling frustratingly circular. (C) Many companies have responded by designing chatbots to recognize their own limits, automatically transferring a frustrated customer to a human agent before the conversation turns into a source of complaint.

주어진 문장: In other words, silence breeds even more silence, feeding a self-reinforcing cycle. Communication scholar Elisabeth Noelle-Neumann proposed the spiral of silence theory to explain why certain opinions dominate public discussion while others fade into invisibility. ( ① ) According to this theory, individuals constantly observe their surrounding environment to judge which opinions are widely accepted and which are not. ( ② ) When people sense that their own view belongs to a minority, they often choose to stay silent rather than risk social isolation or criticism. ( ③ ) This silence, however, creates a distorted impression that the minority opinion is even rarer than it actually is, discouraging additional supporters from speaking up. ( ④ ) Over time, this cycle spirals downward, allowing the dominant opinion to appear increasingly unanimous while dissenting voices disappear from visible conversation. ( ⑤ ) Social media platforms can intensify this spiral, since visibility metrics make popular opinions instantly noticeable while unpopular ones remain hidden.