In tropical regions, certain animals, like the Indian bullfrog (Hoplobatrachus tigerinus) and the common snail (Achatina fulica), utilize a survival strategy known as estivation to cope with extreme heat and prolonged periods of drought. Estivation involves entering a dormant state to conserve energy and minimize water loss during unfavorable environmental conditions, similar to hibernation in colder climates.

The Indian bullfrog estivates by burrowing into mud and secreting a mucous layer that retains moisture and reduces water loss. This adaptation allows them to survive until the return of the rainy season, which provides a cooler and more humid environment. Similarly, the common snail retreats into its shell and secretes a special layer of mucus that hardens and seals the opening, preventing water loss. They remain inactive until environmental conditions improve.

Another example of estivation is seen in the Asian swamp eel (Monopterus albus). These fish burrow into mud during droughts and enter a state of dormancy, reducing their metabolic rate to survive without water for extended periods. They remain in this state until water returns, allowing them to resume normal activities.

Estivation is a critical survival strategy for these animals, enabling them to endure the harsh conditions of the dry season in tropical regions. By reducing their metabolic rates and seeking shelter, they can conserve energy and water until more favorable conditions return, highlighting the resilience and adaptability of these species​

Rising sea levels due to global warming have drastically impacted coastal and low-lying areas worldwide. Estimates suggest that by 2100, around 630 million people could be living on land below projected annual flood levels, potentially forcing them to migrate. Regions like the Solomon Islands, Kiribati, and parts of Bangladesh are particularly vulnerable, with many communities already experiencing displacement due to land loss and coastal erosion. In places such as the Carteret Islands in Papua New Guinea, residents have been relocated due to severe flooding and land degradation. Meanwhile, in Jakarta, Indonesia, land subsidence from groundwater extraction exacerbates flooding risks, prompting the government to plan relocating the capital to Borneo.

The decision to stay or migrate is complex, with many communities opting to build sea walls or elevate their homes instead of relocating. Despite these challenges, the urgent need for global climate action and local adaptation strategies is clear. Efforts to protect and restore natural barriers, such as mangroves and wetlands, are crucial in mitigating the impacts of sea level rise. The situation underscores the importance of supporting vulnerable populations through both mitigation and adaptation measures to safeguard their future.

In 2007, computer scientist Luis von Ahn was working on converting printed books into a digital format. He found that some words were distorted enough that digital scanners couldn’t recognize them, but most humans could easily read them. Based on that finding, von Ahn invented a simple security test to keep automated “bots” out of websites. The first version of the reCAPTCHA test asked users to type one known word and one of the many words scanners couldn’t recognize. Correct answers proved the users were humans and added data to the book-digitizing project.

Passage 1

Most animals can regenerate some parts of their bodies, such as skin. But when a three-banded panther worm is cut into three pieces, each piece grows into a new worm. Researchers are investigating this feat partly to learn more about humans’ comparatively limited abilities to regenerate, and they’re making exciting progress. An especially promising discovery is that both humans and panther worms have a gene for early growth response (EGR) linked to regeneration.

Passage 2

When Mansi Srivastava and her team reported that panther worms, like humans, possess a gene for EGR, it caused excitement. However, as the team pointed out, the gene likely functions very differently in humans than it does in panther worms. Srivastava has likened EGR to a switch that activates other genes involved in regeneration in panther worms, but how this switch operates in humans remains unclear.

It is hard to imagine what life would be like without the contributions engineers have already made. They have not just helped us to survive, be healthy, explore, and move around better but they have also made life more enjoyable through advances in areas such as communications, computing, and sports. Computer engineers, for example, have helped develop devices and software that we can use to make and share documents and home videos, listen to our favorite music, and talk with co-workers, friends, and family members across the globe. In sports, different engineers have made systems and devices that provide us with better, safer equipment, communications that enable teams to interact better and games to be televised, and environments and infrastructure that improve the playing and watching of games.

Text 1

It is through inspiration that a teacher teaches a student to think. Educating is not the business of memorization but the business of inquiry. The student-teacher dichotomy is one of reciprocated wonderment with each party undergoing continuous improvement. And an effective instructor is merely the one responsible for that curiosity in the minds of his or her students. It was Robert Frost who said, “I am not a teacher, but an awakener.”

Text 2

I became a teacher because it was the noblest profession I could think of. Get this: I impart knowledge. I am responsible for instilling the foundation in the next generation of professionals and leaders. It all sounds very romantic, but the job comes down to an ability to simplify and explain those concepts that make up the core curriculum. If I cannot communicate clearly with my students, if I cannot come to their level and make the instruction relevant and accessible, then I fail.

But heating proteins isn’t the only way to denature them: they can also be denatured by adding certain denaturing substances. Many of these substances, like strong acids and bases, you wouldn’t want to add to your food; however, one common denaturing agent is salt. This is why you may want to brine a tougher cut of meat in addition to cooking it. Brining involves soaking something in a solution of salt water. Another benefit of brining is that when the meat absorbs the salt, this draws water into the meat to dilute the salt. Thus, brining also serves to keep meat moist. Some chefs will advise searing the outside of a cut of meat before cooking it through to lock in the moisture. However, chemistry doesn’t support this approach: steam is equally capable of escaping through a seared crust as it is through non-seared meat.

Text 1

According to Darwin’s theory of evolution, all organisms arise and develop through the process of natural selection, or small functional inheritances that boost one’s ability to compete and survive in the wild. When small genetic mutations occur and prove beneficial, they are passed on to offspring, allowing a slow evolution to occur while the less competitive organism dies out. Eventually, Darwin argues, these mutations accumulate and form an entirely new organism.

Text 2

Without having a grasp of Gregor Mendel’s work on heredity, Darwin couldn’t anticipate modern discoveries within genetics such as genetic drift. Darwin himself acknowledged that his theory would encounter challenges if any complex organ were to be found which could not possibly have been formed by successive, slight modifications. With modern advancements in molecular biology and biochemistry, these “irreducibly complex systems” are not only known to exist, but are, in fact, very prevalent on the cellular level.

Ecologically, organic farming is designed to promote and enhance biodiversity, so it must combine scientific knowledge and technologies to stimulate naturally occurring biological processes. For instance, organic farming uses pyrethrin, a natural pesticide found in the chrysanthemum flower, to deter pests, and potassium bicarbonate to control disease and suppress unruly weeds. Furthermore, where conventional farming focuses on mass production of each individual crop, organic farming encourages polyculture, or multiple crops being raised in the same space.

Our observations suggest increasingly that Earth-size planets orbiting within the habitable zone may be common in the galaxy-current estimates suggest that more than 40 percent of stars have at least one. But are any of them inhabited? With no ability to send probes there to sample, we will have to derive the answer from the light and other radiation that come to us from these faraway systems. If we manage to separate out a clean signal from the planet and find some features in the light spectrum that might be indicative of life, we will need to work hard to think of any non biological process that might account for them. We also might not be able to detect biospheres even if they exist.

In general, deep ocean habitats will be affected by tidal current energy systems due to the change of water flows, materials in the ocean floor, and movement of sediment. Potential other effects include mortality of fish passing through turbines (blade-strike) and the collision risk of marine mammals. A study showed that change in sediment patterns will most likely follow the installation of tidal arrays, impacting the local underwater habitat. This, in turn, could impact animal and plant species. Species of marine mammals and fish could experience distress and discomfort. However, Lewis et al. contend that, "while current technologies have moving parts (rotating rotor blades or flapping hydrofoils) that may harm marine life, there is no evidence to date of harm from tidal current devices to larger marine animals, such as whales, dolphins, seals, and sharks".

PASSAGE 1

There comes a time in every boy’s life when he is placed on an island to compete for a million dollars, only to discover that money doesn’t buy happiness. He meets his soul mate on national television, picks her out of a lineup of twenty, and later moves to the suburbs to redecorate the neighbors’ house. This, apparently, is real life—according to television networks.

Reality TV claims to portray real life, but it rarely does. It's cheaper to produce than scripted shows and extremely popular, yet far removed from genuine human experience. Shows like American Idol promise dreams of stardom but often feature judges more focused on insults than mentoring. Dating shows turn romance into competition, often placing more value on appearances than character. If this is reality, we’re in trouble.

Decorating shows take things further. Couples swap homes and redecorate—but with the help of designers who often suggest bizarre makeovers like covering a room in muslin or gluing plastic flowers on bathroom walls. Because everyone is on camera, reactions are staged, not authentic.

Survivor, the show that launched the Reality TV craze, drops contestants in the wild to outwit each other for a million dollars. But viewers aren’t watching survival skills—they’re watching tired, hungry people argue and complete silly challenges. Outside the show, many of these “survivors” live comfortably, far from any jungle.

Networks now prioritise these cheap, dramatic formats over original comedies and dramas. The result is hours of programming each week featuring real people in unrealistic, manipulated scenarios. Despite being labeled “reality,” these shows often feel more fictional than scripted TV. When people act for cameras in engineered situations, what’s real about that?

PASSAGE 2

Why does Reality TV get such a bad reputation? Critics blame it on declining morals and shorter attention spans. Yet, reality-based programming has existed for decades—Candid Camera in 1948, CBS’s Wanted in the 1950s, and even a 1973 PBS documentary filmed in a family’s home. Still, it was Survivor in 2000 that sparked the genre’s explosion. Today, over 40 reality shows air, and in 2002 the Emmys added a “Best Reality Show” category.

So why are these shows so popular? Have our standards really slipped? The Real World, for example, has run for over ten years. It places strangers together under one roof and films their interactions. The participants are often young, attractive, and chasing fame, with many even hiring agents before filming begins.

Other shows like American Idol, Star Search, and Fame give singers, dancers, and actors a shot at professional success. Even those who don’t win benefit from national exposure. Survivor adds a new twist: the promise of fame and a million-dollar prize. Shows like Big Brother and Fear Factor build on this model—offering large rewards in exchange for endurance, stunts, and constant surveillance.

So, what’s the issue? Reality TV often hinges on two motivators: fame and money. And it works. Many contestants—waiters, stylists, bankers—have become household names. They turn brief exposure into lasting celebrity. Even if you’re not interested in fame, the appeal of big money is undeniable. Watching people face their fears or live in dramatic circumstances for a reward makes for compelling entertainment.

Ultimately, Reality TV is about dreams—of wealth, recognition, and transformation. While not everyone approves, the genre taps into human ambition. If you don’t enjoy it, there’s always the option to change the channel. But for many, the blend of competition, spectacle, and aspiration remains irresistible.

Experts say that if you feel drowsy during the day, even during boring activities, you haven’t had enough sleep. If you routinely fall asleep within five minutes of lying down, you probably have severe sleep deprivation, possibly even a sleep disorder. Microsleeps, or very brief episodes of sleep in an otherwise awake person, are another mark of sleep deprivation. In many cases, people are not aware that they are experiencing microsleeps. The widespread practice of “burning the candle at both ends” in Western industrialized societies has created so much sleep deprivation that what is really abnormal sleepiness is now almost the norm.

Many studies make it clear that sleep deprivation is dangerous. Sleep-deprived people who are tested by using a driving simulator or by performing a hand-eye coordination task perform as badly as or worse than those who are intoxicated. Sleep deprivation also magnifies alcohol’s effects on the body, so a fatigued person who drinks will become much more impaired than someone who is well rested. Driver fatigue is responsible for an estimated 100,000 motor vehicle accidents and 1,500 deaths each year, according to the National Highway Traffic Safety Administration. Since drowsiness is the brain’s last step before falling asleep, driving while drowsy can—and often does—lead to disaster. Caffeine and other stimulants cannot overcome the effects of severe sleep deprivation. The National Sleep Foundation says that if you have trouble keeping your eyes focused, if you can’t stop yawning, or if you can’t remember driving the last few miles, you are probably too drowsy to drive safely.

Could good dental hygiene be man’s earliest custom? The findings of paleontologist Leslea Hlusko suggest that 1.8 million years ago early hominids used grass stalks to clean their teeth. Many ancient hominid teeth unearthed in archaeological digs have curved grooves near the gumline. Hlusko posited that these grooves were evidence of teeth cleaning by early man. However, critics pointed out that even though the use of toothpicks is still a common practice among modern man similar grooves are not found on modern teeth.

Hlusko, convinced that she was on the right track, experimented with grass stalks to see if they might have been the cause of the grooves. Unlike the wood used for modern toothpicks, grass contains hard silica particles that are more abrasive than the soft fibers found in wood. A stalk of grass is also about the same width as the marks found on the ancient teeth. To prove her theory Dr. Hlusko took a baboon tooth and patiently rubbed a grass stalk against it for eight hours. As she suspected, the result was grooves similar to those found on the ancient hominid teeth. She repeated the experiment with a human tooth and found the same result.

It seems that our early human ancestors may have used grass, which was easily found and ready to use, to floss between their teeth. As Hlusko suggests in the journal Current Anthropology, “Toothpicking with grass stalks probably represents the most persistent habit documented in human evolution.”