영어 모의고사 (자동 편성)

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

Exercise does far more than strengthen muscles and the heart; it also produces ① 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 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 performs ③ 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, delivering oxygen and nutrients more efficiently, while also ④ raising levels of stress hormones that can interfere with clear thinking. Interestingly, aerobic activities such as running or swimming appear to produce more ⑤ pronounced cognitive benefits than purely strength-based training.

Sleep hygiene refers to a set of simple daily habits that help the body prepare for consistent, ① restorative rest. Experts commonly recommend going to bed and waking up at the same time every day, even on weekends, because an irregular schedule ② clarifies the body's internal clock and makes it harder to fall asleep on demand. They also advise reserving the bedroom for sleep alone, since using the bed to study, scroll through a phone, or watch videos teaches the brain to associate that space with ③ wakeful activity rather than rest. Physical environment matters as well: a cool, dark, and quiet room tends to produce ④ deeper sleep than one that is warm, bright, or noisy. None of these individual habits guarantees a good night's sleep on its own, but together they form a routine that gradually trains the body to expect and enter sleep more easily, much the way a ⑤ consistent set of cues trains an athlete's body to perform at a certain time each day.

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. 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. If a nap extends much beyond that window, _______________. 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. 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. For this reason, many workplaces now designate quiet rooms where employees can recharge briefly during the day.

Team sports place athletes in a uniquely social form of competition, one where individual skill alone rarely determines the outcome of a match. Sports psychologists have long studied why some groups of talented individual players fail to perform as a cohesive unit while other, less individually skilled teams consistently exceed expectations. Trust among teammates appears to be a decisive factor, since _______________. Clear and consistent communication during high-pressure moments further reduces the hesitation and confusion that can unravel a team's coordination in front of a crowd.

Scientists have identified certain gene variants that appear more frequently among elite endurance athletes than among the general population, along with a separate set that seems to favor explosive, power-based sports such as sprinting. (A) However, researchers caution strongly against interpreting these findings as evidence that athletic greatness is simply inherited. (B) One frequently studied variant, for instance, influences the proportion of slow-twitch versus fast-twitch muscle fibers a person naturally develops, a ratio that shapes whether a body leans toward endurance or explosive power. (C) Genetics may set a rough ceiling on an individual's ultimate potential, but where any particular athlete lands within that range depends overwhelmingly on training quality, nutrition, coaching, and sheer determination.

Ambitious young athletes and the parents who support them sometimes assume that more training automatically produces better results, a belief that occasionally leads to a condition known as overtraining syndrome. (A) Warning signs are often subtle at first, including disrupted sleep, irritability, and a loss of enthusiasm for a sport the athlete once genuinely enjoyed, which adults often mistake for ordinary moodiness. (B) Unlike ordinary fatigue that resolves after a few days of rest, overtraining syndrome develops gradually over weeks or months of insufficient recovery, eventually producing persistent exhaustion and declining performance despite continued hard work. (C) Adolescents may be especially vulnerable to this condition, since their bodies are simultaneously coping with the physical demands of growth and the added stress of intensive training schedules.

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. 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. ( ① ) Far from being mere superstition, this consistent sequence, whether it involves bouncing a basketball a fixed number of times or taking a particular number of practice swings, serves a genuine cognitive purpose. ( ② ) Repeating the same physical and mental steps before every attempt narrows an athlete's focus away from distracting thoughts about outcome or crowd noise and toward the specific technical cues needed to execute the skill correctly. ( ③ ) The routine essentially functions as a trigger, cuing the body to shift automatically into a familiar, well-rehearsed state. ( ④ ) For this reason, coaches now actively teach young athletes to develop and rehearse individualized routines rather than treating them as personal quirks. ( ⑤ )

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

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.