영어 모의고사 (자동 편성)

Every day, email providers quietly block billions of unwanted messages before they ever reach a user's inbox, a task that ① would be impossible without an AI filtering system running constantly in the background. The filter examines each incoming message for suspicious patterns, including certain keywords, unusual sender addresses, and formatting tricks that scammers commonly rely on ② to slip past detection. What makes the system effective is that it keeps ③ learning after launch: whenever a user marks a message as spam or rescues a message mistakenly filtered out, that action ④ become new training data, sharpening the filter's future decisions. This creates a constant back-and-forth, since spammers study which messages get blocked and then adjust their wording to slip through again, ⑤ resulting in an ongoing contest between each side.

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

Within days, thousands of people began recreating the dance and tagging the brand, turning an ordinary product launch into a ①viral trend. Because participants created the content themselves, viewers found the videos far more ②entertaining than a traditional advertisement would have been. The company barely spent any money on production, yet the challenge reached ③millions of viewers across multiple platforms. Encouraged by this success, other brands quickly attempted similar challenges, though many ④succeeded in generating the same excitement. Researchers later explained that the original challenge succeeded because it felt spontaneous and fun rather than obviously ⑤commercial.

A growing number of people are practicing what is now called digital detox, the deliberate decision to stop using smartphones for a set period. Rather than checking notifications every few minutes, participants unplug for a weekend, a week, or sometimes even longer. Numerous studies suggest that this temporary withdrawal produces real benefits for both the mind and the body. First, attention spans fragmented by constant notifications gradually recover, allowing people to concentrate on single tasks for longer stretches. Second, avoiding screens before bedtime improves sleep quality, since blue light emitted by devices is known to disrupt natural sleep cycles. Third, people freed from their phones often rediscover the pleasure of face-to-face conversations that had been replaced by texting. Critics argue that complete disconnection is impractical in a hyperconnected society, yet even brief, regular breaks appear to restore balance. Therefore, _______________.

Across many countries, high schools begin classes early in the morning, often before eight o'clock. This schedule assumes that teenagers can simply go to bed earlier to compensate, but biology tells a different story. During adolescence, the body's internal clock shifts later, delaying the release of melatonin until well after ten at night. As a result, most teenagers are not physiologically ready to fall asleep until much later than younger children or adults. When early start times force them to wake before their bodies have completed a full sleep cycle, the mismatch accumulates into a chronic sleep debt that affects concentration and mood throughout the school day. Researchers who study this mismatch argue that _______________. Some school districts that delayed their start times by thirty minutes reported improvements in attendance, suggesting that the timing of the school day matters more than commonly assumed.

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 compress much of that work into a short conversation, generating a full day-by-day itinerary within minutes. Many travelers appreciate having a solid starting point rather than a blank page. Still, seasoned travelers warn that _______________.

The two-minute rule offers a simple but powerful strategy for anyone who struggles to begin a new habit. (A) Once the habit of showing up regularly is established, the duration or intensity of the activity can gradually increase without much resistance. (B) The idea behind this rule is that most people quit a new habit not because the activity itself is difficult, but because starting feels intimidating. (C) By reducing a habit to something as simple as reading one page or doing one push-up, the initial hesitation to begin nearly disappears.

Wearable devices that track sleep have become enormously popular, promising a detailed breakdown of light, deep, and REM sleep each night. (A) Despite these limitations, many users have come to treat the nightly score generated by their device as an objective medical verdict, sometimes experiencing anxiety when the number falls below what they expect, a phenomenon researchers have begun calling orthosomnia. (B) Independent studies comparing wearable data with polysomnography, the gold-standard method used in clinical sleep labs, have found that consumer devices are reasonably accurate at distinguishing sleep from wakefulness but considerably less reliable at identifying specific sleep stages. Some trackers overestimate deep sleep, while others underestimate the amount of time spent in REM sleep, and the margin of error can vary widely between brands. (C) These gadgets typically rely on movement sensors and heart rate monitors to estimate sleep stages, since directly measuring brain activity would require equipment found only in a sleep laboratory. This indirect approach, however, introduces significant uncertainty.

This process, though it may sound simple, triggers a remarkable series of adaptations throughout the cardiovascular system. Aerobic exercise, such as jogging, swimming, or cycling at a steady pace, strengthens the heart by forcing it to pump larger volumes of blood with each beat. ( ① ) 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 fewer times per minute. ( ② ) This adaptation explains why trained athletes often have a much lower resting heart rate than sedentary individuals of the same age. ( ③ ) Beyond the heart itself, aerobic activity encourages the body to build new capillaries within muscle tissue, improving the delivery of oxygen and nutrients at a cellular level. ( ④ ) Researchers have also found that regular aerobic exercise reduces inflammation throughout the body and improves the way cells respond to insulin. ( ⑤ )

주어진 문장: This limitation means the technology has not yet fully replaced conventional factories. Three-dimensional printing technology is changing how products are designed and manufactured across many industries. ( ① ) Unlike traditional manufacturing, which often requires expensive molds and long production times, 3D printers can create complex objects directly from digital files within hours. ( ② ) This flexibility allows companies to produce small batches of customized products without the massive costs typically associated with mass production. ( ③ ) Hospitals now use 3D printing to create prosthetic limbs tailored precisely to individual patients, while automakers use it to build lightweight parts. ( ④ ) However, experts caution that 3D printing still struggles to match the speed of mass production for extremely large orders. ( ⑤ ) As printing materials improve and machines become faster, the technology is expected to play an increasingly central role in future manufacturing.