영어 모의고사 (자동 편성)

Bacteria have been cutting up invading viral DNA for billions of years, long before any scientist ①thought to borrow the trick for use in a laboratory. The CRISPR-Cas9 system, as it is now known, relies on a short guide RNA that matches a specific DNA sequence, ②lead a scissor-like enzyme called Cas9 directly to that exact location in the genome. Once Cas9 arrives at the target site, it slices both strands of the DNA helix, and the cell's own repair machinery rushes in ③to mend the cut, often introducing a small change in the process. By supplying the cell with a template during this repair step, scientists can direct that machinery ④to insert a specific new sequence rather than merely disabling the original gene. What once required years of painstaking work to alter a single gene can now, with a properly designed guide RNA, ⑤be accomplished within days, a shift in speed that has reshaped nearly every corner of biological research.

Athletes preparing for major endurance events sometimes train for weeks at high altitude, where the air contains ①less oxygen than at sea level, in hopes of gaining a physiological edge once they return to compete at lower elevations. In this thin air, the body responds by producing ②fewer red blood cells, which carry oxygen more efficiently through the bloodstream to working muscles. When these athletes return to sea level, where oxygen is more abundant, their blood retains this elevated capacity for a limited period, potentially translating into ③improved endurance performance. However, the benefits of altitude training are far from guaranteed, since individual athletes respond quite ④differently to the same conditions, and some experience excessive fatigue that undermines the very training they hoped to complete. Many elite programs therefore follow a strategy known as live high, train low, in which athletes sleep at altitude to ⑤stimulate blood adaptations but perform intense workouts at lower elevation to maintain quality and intensity.

A shocking headline can spread across social media within minutes, long before anyone checks whether it is actually true. Studies show that false stories often travel ①slower than accurate ones, partly because surprising or emotional claims get shared more quickly than careful, balanced reporting. To handle this flood of information, students today need a skill that previous generations rarely had to practice: checking a source before believing it. Simple habits can make a ②real difference, such as looking for the original source of a claim, checking the date an article was published, and searching to see whether other trustworthy outlets are reporting the same story. Media literacy classes now teach students to ③pause before they share anything, asking who wrote it and why. This small pause, teachers say, is often the only thing standing between a curious reader and a piece of ④convincing misinformation, protecting not only the reader but everyone in their online ⑤network.

Imagine a brilliant scientist named Mary who has spent her entire life inside a black-and-white room, learning everything physical science could ever teach about color, including the exact wavelengths of light and the precise neural processes triggered when a person sees red. Despite this complete physical knowledge, Mary herself has never actually seen a color; every book, screen, and object in her world has been carefully restricted to shades of gray. Suppose that one day Mary is finally released from the room and shown a ripe red tomato for the first time. Philosopher Frank Jackson argued that Mary would learn something entirely new at that moment, namely what it actually feels like to see red, even though she already possessed every physical fact about color there was to know beforehand. If Mary genuinely gains new knowledge upon leaving the room, then _______________.

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. Unlike ordinary fatigue that resolves after a few days of rest, overtraining syndrome develops gradually over weeks or months of insufficient recovery relative to training load, eventually producing persistent exhaustion, declining performance despite continued hard work, and increased susceptibility to illness and injury. 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. Recovery from full-blown overtraining syndrome can take months rather than days, which is why _______________.

Anyone who has tried to name the ink color of a word like red printed in blue letters knows how surprisingly difficult the task can feel. This everyday struggle, known as the Stroop effect, deserves more attention than casual curiosity grants it, because it reveals something fundamental about how the mind allocates its limited resources. Reading a familiar word is an automatic process practiced so extensively since childhood that it proceeds almost involuntarily, whereas naming a color requires deliberate, controlled attention. When these two processes point toward conflicting answers, _______________. Educators should not dismiss this delay as a trivial curiosity confined to laboratories, since the same competition between habit and intention underlies far more consequential situations, such as a driver's struggle to resist checking a phone despite knowing the danger. Recognizing how automatic responses can hijack conscious intentions is essential for designing environments, from classrooms to highways, that support rather than undermine our efforts at self-control.

Social media researchers use the term context collapse to describe what happens when a single online post reaches audiences that would normally remain separate in offline life. In daily interactions, people naturally adjust their tone and content depending on whether they are speaking with family, close friends, or professional colleagues. However, a typical social media feed merges these distinct audiences into one undivided crowd, since a single post can simultaneously reach parents, employers, and casual acquaintances. Consequently, users often struggle to decide which version of themselves to present, knowing that a joke suitable for close friends might seem unprofessional to a supervisor. For example, a party photo posted for friends could later damage someone's reputation if an employer notices it. This tension forces many users to either self-censor heavily or maintain multiple separate accounts tailored to different audiences. Understanding context collapse _______________.

Behavioral economists use the term status quo bias to describe a tendency to prefer the present situation over a new alternative, even when the alternative would bring greater benefits. This bias helps explain why many households hesitate to switch to renewable energy, such as installing solar panels on their roofs. Although solar panels can lower electricity bills over time, homeowners often stick with their current power source because it feels safe and requires no immediate effort. In contrast, switching demands research, upfront cost, and trust in unfamiliar technology, all of which can seem risky compared with doing nothing. For example, a neighborhood association might repeatedly postpone a vote on shared solar panels, not because the plan is flawed, but because members are reluctant to leave their routine. Therefore, boosting renewable adoption may depend less on proving its advantages and more on _______________.

Researchers who study teenagers have found a strong link between how well students sleep and how well they perform in school. (A) 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. (B) 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. (C) 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. 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.

In short, an effective fueling plan treats carbohydrate loading as one tool among many, not a substitute for well-rounded nutrition. In the days leading up to an endurance event, many athletes deliberately increase their carbohydrate intake while reducing training volume, a practice known as carbohydrate loading. ( ① ) The strategy is designed to maximize the amount of glycogen, the storage form of carbohydrate, packed into muscle tissue before competition begins. ( ② ) 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 call hitting the wall. ( ③ ) Sports nutritionists caution, however, that the timing and composition of meals matter as much as the total quantity of carbohydrate consumed, since eating unfamiliar foods immediately before competition can cause digestive discomfort. Athletes are therefore advised to practice their nutrition strategy during training rather than experimenting with it for the first time on race day. ( ④ ) Beyond carbohydrates, adequate protein and micronutrient intake throughout the training cycle remains essential, since fueling strategy is only one part of a much larger nutritional picture. ( ⑤ )