영어 모의고사 (자동 편성)

Many people believe that a new habit becomes automatic after only twenty-one days, but researchers who ①examined real behavior found a different number. This project, ②called the 66-day habit formation study, tracked volunteers who tried to adopt a new daily habit, like drinking water with lunch. Researchers measured how automatic each action felt over time and found that habits ③needing an average of sixty-six days to become effortless. Yet the actual time varied widely, ranging from about eighteen days for simple habits to over two hundred days for ④difficult ones. This wide range explains why the popular twenty-one-day claim, though easy ⑤to remember, rarely matches real experience.

Wearable devices ①that track sleep have become enormously popular, promising a detailed breakdown of light, deep, and REM sleep each night. These gadgets typically rely on movement sensors and heart rate monitors ②to estimate sleep stages, since directly measuring brain activity would require equipment found only in a sleep laboratory. Independent studies ③compares 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 ④underestimate the amount of time spent in REM sleep, and the margin of error can vary widely between brands. Despite these limitations, many users have come ⑤to 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.

Even a modest level of dehydration, as little as two percent of body weight ①lost through sweat, can measurably reduce an athlete's endurance and cognitive sharpness during competition. As fluid levels drop, blood volume decreases, ②forcing the heart to work harder to deliver the same amount of oxygen to working muscles, which accelerates fatigue. Dehydration also impairs the body's ability ③to regulate its own temperature, since sweating is the primary mechanism for releasing excess heat during intense exercise. Athletes competing in hot, humid conditions face a particularly difficult balance, because sweating heavily to stay cool simultaneously ④depletes the very fluids needed to sustain performance. For this reason, sports scientists generally recommend a hydration strategy ⑤tailoring to an individual athlete's sweat rate and the specific conditions of the event.

A smart thermostat that learns a family's daily rhythm can lower the temperature automatically before everyone wakes up cold, while smart lights ①that follow a resident's schedule no longer need to be switched on and off by hand. These small conveniences rest on a shared foundation: sensors collect data about temperature, motion, and light throughout the home, and an algorithm gradually learns ②which settings match each household's actual habits rather than a factory default. Over months of use, the system becomes noticeably better at ③anticipate needs, often adjusting settings moments before a resident would have reached for a switch. Yet convenience comes with a trade-off that many households ④overlook. Every one of these small adjustments depends on constant data collection, meaning that a detailed record of when people wake, leave, and return home is quietly ⑤being stored somewhere beyond their immediate control.

When a price is crossed out and replaced with a lower number, consumers instinctively perceive the new price as a ①loss, even if the original price was rarely charged. Limited-time sales further ②intensify this effect, since a ticking clock encourages rushed decisions that leave little room for careful comparison. Retailers also use phrases such as "while supplies last" to suggest ③scarcity, even when inventory remains plentiful. Over time, frequent sales can actually train customers to wait for discounts rather than buy at full price, which can ④hurt long-term profits. Despite this risk, many companies continue relying on sales events because the short-term boost in customer traffic usually ⑤outweighs the potential downside.

Many people feel a ①sudden wave of anxiety when their smartphone battery is nearly dead or they have left it at home. This ②intense discomfort, known as nomophobia, is short for "no-mobile-phone phobia." Researchers explain that this fear develops because smartphones have become ③tightly linked to social belonging; missing a notification can feel like being cut off from friends. Therefore, experts suggest gradually reducing phone checks to ④strengthen this anxious dependence. Recognizing nomophobia as a real psychological pattern is the first step toward a ⑤healthier relationship with technology.

For centuries, dreams have fascinated 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, _______________. Another theory proposes that dreams serve a more practical function, allowing the brain to rehearse 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 information rather than serving any independent purpose of its own.

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.

The growing sophistication of cyberattacks has transformed cybersecurity into one of the most in-demand career fields. (A) Universities have responded to this trend by launching specialized degree programs focused entirely on cybersecurity. (B) As a result, businesses across nearly every industry now compete to hire qualified security professionals. (C) Hackers today target organizations of every size, from small retailers to major financial institutions.

This grogginess occurs because the brain has not fully completed a sleep cycle and is abruptly pulled out of its deepest phase. A short nap taken in the early afternoon, often called a power nap, can noticeably sharpen attention and mood without leaving a person groggy afterward. ( ① ) The key lies in timing: naps limited to roughly twenty minutes allow the brain to pass through the lightest stages of sleep while avoiding the deeper stages associated with slow-wave activity. ( ② ) If a nap extends much beyond that window, the sleeper risks waking during deep sleep, which produces a foggy, disoriented feeling known as sleep inertia that can persist for thirty minutes or more. ( ③ ) Laboratory studies comparing napping and non-napping groups have repeatedly shown that a brief nap improves reaction time and short-term memory almost as effectively as a full night of extra rest. ( ④ ) Interestingly, the benefit appears strongest when the nap occurs several hours after waking, since this is when the body's natural dip in alertness makes rest most effective. ( ⑤ ) For this reason, many workplaces now designate quiet rooms where employees can recharge briefly during the day.