Exam 4: HESI-A2-Reading
Exam 1: HESI-A2-Chemistry175 Questions
Exam 2: HESI-A2-Math252 Questions
Exam 3: HESI-A2-Vocabulary249 Questions
Exam 4: HESI-A2-Reading326 Questions
Exam 5: HESI-A2-Grammar361 Questions
Exam 6: HESI-A2-Biology165 Questions
Exam 7: HESI-A2-Physics242 Questions
Exam 8: HESI-A2-Anatomy & Physiology314 Questions
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Concussions
Concussions are brain injuries that occur when a person receives a blow to the head, face, or neck. Although most people who suffer a concussion experience initial bouts of dizziness, nausea, and drowsiness, these symptoms often disappear after a few days. The long-term effects of concussions, however, are less understood and far more severe.
Recent studies suggest that people who suffer multiple concussions are at significant risk for developing chronic traumatic encephalopathy (CTE), a degenerative brain disorder that causes a variety of dangerous mental and emotional problems to arise weeks, months, or even years after the initial injury. These psychological problems can include depression, anxiety, memory loss, inability to concentrate, and aggression. In extreme cases, people suffering from CTE have even committed suicide or homicide. The majority of people who develop these issues are athletes who participate in popular high-impact sports, especially football.
Improvements in diagnostic technology have provided substantial evidence to link severe-and often fatal-psychological disorders to the head injuries players receive while on the field. Recent autopsies performed on the brains of football players who have committed suicide have shown advanced cases of CTE in every single victim.
In response to the growing understanding of this danger, the National Football League (NFL) has revised its safety regulations. There is hope that these new regulations, coupled with advances in helmet design, will reduce the number of concussions player endure, and thus curb the number of CTE cases. Efforts by the NFL and other professional sports leagues are certainly laudable. However, new regulations at the professional level cannot protect amateur players, especially young people. Fatal cases of CTE have been reported in victims as young as 21. With appropriate equipment and form, tackling need not be dangerous. Proper tackling form-using the arms and shoulders to aim for a player's midsection rather than leading with the top of the head-should be taught at an early age. Youth, high school, and college leagues should also adopt safety rules even more stringent than the NFL's.
Question: Why does the author include the detail "fatal cases of CTE have been reported in victims as young as 21" in the passage?
(Multiple Choice)
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Soda Ban
Cigarettes. Alcohol. Drugs. Most people agree that these things should be kept away from children and only consumed by adults in limited quantities, if at all. Is the same thing true for soda?
A 20-ounce-bottle of soda has over sixteen teaspoons of sugar in it. This is twice the amount of sugar that the American Heart Association recommends a person should eat in an entire day. Furthermore, this 20-ounce bottle of soda delivers over 200 calories and no nutritive value; soda contains no vitamins, minerals, fiber, protein, or other nutrients.
Drinking sodas and other sugary beverages can cause serious health problems. Consuming too many of these sugar-filled beverages may increase your risk for developing Type 2 diabetes, obesity, heart disease, tooth decay, and certain kinds of cancer. Studies have also shown that people who drink soda tend to develop a condition known as metabolic syndrome. Metabolic syndrome is a condition characterized by excess abdominal fat, high blood pressure, elevated blood sugar, high levels of triglycerides, and low levels of HDL cholesterol (commonly referred to as "good cholesterol").
Some places have already taken steps to reduce the amount of soda people consume. In California, for example, cafeterias and vending machines in grade schools can not sell soda. The city of Philadelphia also recently added a tax on sugary beverages, making sodas more expensive to purchase.
Soda may taste good, but it is terrible for your health. There should be more bans and taxes to keep people from drinking these harmful beverages.
Which detail supports the idea that people have taken action against soda?
(Multiple Choice)
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Mercury in Fish
Mercury is a highly toxic metal found in neon signs, fluorescent lights, older thermometers, and certain kinds of telescopes. It can also be found in something that many people eat on a regular basis: fish. The mercury we might find in a can of tuna is most likely an indirect result of the coal industry. Mercury, which is naturally found in coal, is released into the air when coal is burned. It finds its way into waterways via mercury-laced rain.
Mercury accumulates in certain kinds of fish through a process called biomagnification. Biomagnification occurs when a substance enters the food chain in small amounts at the very bottom and then increases in concentration in animals higher up on the food chain. Once a fish eats another creature containing mercury, the mercury does not leave that fish's body, but instead is stored in fat. Therefore, the mercury continually accumulates as more mercury-contaminated fish are eaten.
Despite the toxicity of mercury and the widespread nature of fish contamination, there is no need for the public to be overly apprehensive. Many popular fish, such as salmon, catfish, or tilapia, are generally safe to eat. Other fish, especially tuna and grouper, should only be eaten in moderation. Young children and pregnant women should be especially cautious about how many servings of mercury-contaminated fish they have per week. It is recommended that people in these groups not eat more than 2 servings of mercury-contaminated fish per week. Fish with the highest levels of mercury include shark, swordfish, and king mackerel. All people should avoid eating large amounts of these kinds of fish, and no one should eat these fish more frequently than once a month.
Question: What is the best summary of this passage?
(Multiple Choice)
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In 1958, the magazine Popular Science predicted that the "age-old dream of flying like a bird may be closer than we think." How was this supposed to come to pass? The magazine predicted that people would be flying around with the greatest of ease using rocket-powered jetpacks. Indeed, such means of locomotion exist today. But there are many hurdles to pass before they become widely used. They are literally rockets, so they make a terrible racket-up to 130 decibels, which is actually louder than a 747 at takeoff. They're heavy, too. At eighty-five pounds, they're far too heavy for use by the majority of the population today. Finally, they're extremely costly. Entry-level jetpacks go for around a quarter of million dollars. And prices soar upwards from there. So while personal jetpacks are a great idea in theory, reality will prevent them from becoming a viable source of transportation anytime soon.
What is the main idea of the passage?
(Multiple Choice)
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Fibromyalgia
Fibromyalgia is a chronic condition that affects an estimated 3-6% of the world's population. The disorder is characterized by both physiological and psychological symptoms, including nerve pain, fatigue, sleep and mood disturbances, headaches, bowel problems, and incontinence. The exact cause of fibromyalgia is unknown.
For some people, fibromyalgia symptoms begin after some sort of physical or psychological stress. However, for others, the onset of symptoms is gradual. Research has shown that genetics may play a part, but there is also evidence that environmental factors can contribute.
The wide variety of symptoms made it difficult to diagnose and treat for many years, though recent research has made some promising advances. Although a cure for fibromyalgia has not yet been developed, research has shown that some of the symptoms can be treated with pharmaceuticals, such as tricyclics or gabapentinoids, or non-pharmacological methods, such as meditation, mindfulness, and cognitive behavior therapy.
The most successful pharmacological treatment for fibromyalgia has been tricyclic antidepressants, such as amitriptyline and nortriptyline. These drugs increase the levels of the neurotransmitters serotonin and norepinephrine, which are often found at decreased levels in the brains of people who suffer from chronic pain. By boosting endorphins and relaxing muscles, tricyclics can ease some of the musculoskeletal pain felt by people with fibromyalgia.
Question: Which of the following statements would the author most likely agree with?
(Multiple Choice)
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Fibromyalgia
Fibromyalgia is a chronic condition that affects an estimated 3-6% of the world's population. The disorder is characterized by both physiological and psychological symptoms, including nerve pain, fatigue, sleep and mood disturbances, headaches, bowel problems, and incontinence. The exact cause of fibromyalgia is unknown.
For some people, fibromyalgia symptoms begin after some sort of physical or psychological stress. However, for others, the onset of symptoms is gradual. Research has shown that genetics may play a part, but there is also evidence that environmental factors can contribute.
The wide variety of symptoms made it difficult to diagnose and treat for many years, though recent research has made some promising advances. Although a cure for fibromyalgia has not yet been developed, research has shown that some of the symptoms can be treated with pharmaceuticals, such as tricyclics or gabapentinoids, or non-pharmacological methods, such as meditation, mindfulness, and cognitive behavior therapy.
The most successful pharmacological treatment for fibromyalgia has been tricyclic antidepressants, such as amitriptyline and nortriptyline. These drugs increase the levels of the neurotransmitters serotonin and norepinephrine, which are often found at decreased levels in the brains of people who suffer from chronic pain. By boosting endorphins and relaxing muscles, tricyclics can ease some of the musculoskeletal pain felt by people with fibromyalgia.
Question: What is the author's main purpose for writing this passage.
(Multiple Choice)
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Your Bones
At birth, the human body contains over 270 bones. However, as the body grows, some of these bones fuse together. The average adult body contains 206 bones. Together, these bones form the skeleton. The skeleton has many vital functions, including protecting internal organs, providing support, enabling movement, generating blood cells, storing calcium, and helping to regulate the endocrine system.
Although we only have one skeleton, it is divided into two major regions: the axial and the appendicular skeletons. The former refers to everything on the body's middle axis, such as the skull, sternum, and vertebrae, while the latter refers to the bones that make up the arms, legs, pelvis, and shoulder girdle. These bones include the femur, the tibia, the ulna, and the radius.
Bones are further classified according to their shape and function. The five classifications of bones are: long, short, flat, irregular, and sesamoid bones. Long bones include the fibula and tibia. The carpal bones in the wrist are examples of short bones. Flat bones are thin and curved, and include the ribs, the sternum, and some skull bones. Irregular bones, such as the vertebrae and some facial bones, have complex shapes. Finally, sesamoid bones are small, round bones that form in tendons. There are sesamoid bones in the hands, wrists, and feet, but the most familiar sesamoid bone is the patella, or kneecap.
Question: Based on the description in the passage, which bone(s) is/are considered to have a complicated structure?
(Multiple Choice)
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Hiccups
At some point in your life, you have probably had the hiccups. Hiccups are caused by spasms in the diaphragm, a muscle located at the bottom of your chest. As we inhale, the diaphragm contracts, pulling air into the lungs. As we exhale, the diaphragm relaxes, pushing air back out through the mouth and nose. When we hiccup, the diaphragm jerks downward suddenly, pulling a quick burst of air into our lungs. As the air rushes into your body, it hits the voice box. This causes your vocal cords to snap shut, creating the sound we recognize as a hiccup.
Hiccups can be triggered by many different things-eating too much, drinking too fast, sudden change of temperature, stress, fatigue, nervousness, and even excessive laughter can all cause the hiccups. While there are many home remedies for hiccups, there is no evidence to suggest that any of them are actually effective. In fact, most cases of the hiccups go away on their own.
Although hiccups are usually harmless, they can be a sign of something more serious. Long-term hiccups might be a result of damage to the nerves that serve the diaphragm muscle. Persistent hiccups might also be caused by certain central nervous system disorders, traumatic brain injuries, drug abuse, or kidney disease.
Question: What is the meaning of the word spasms in paragraph 1?
(Multiple Choice)
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The Science of Taste
Have you ever looked at your tongue in a mirror? If so, you have probably noticed that it is bumpy. The bumps on your tongue are called papillae. Each one of the papillae contains hundreds of taste buds. You also have taste buds on the roof of your mouth and on your epiglottis, which is located at the top of your throat. The taste buds send messages to your brain that tell you about its basic flavor-that is, whether you are eating something salty, sweet, bitter, sour, or umami. Umami is hard to describe, but it is most often called a "meaty" or "savory" flavor. Foods with an umami flavor include meat broth, cheese, and soy sauce.
Your mouth and tongue also have receptors that send information about things besides the basic flavors of food. Your mouth has temperature receptor cells that can tell whether a food is piping hot or ice cold. Other receptors give information about the texture of food or how spicy it is.
But just being able to tell whether what you are eating is sour, cold, crunchy, or spicy is not truly tasting the food. For example, orange soda and root beer are both sweet, cold, and bubbly, but they do not taste the same. In order to get the full flavor of your food, you also need to use your sense of smell. The upper part of your nose contains special cells called olfactory receptors. They send messages about what things smell like to your brain. As you chew your food, chemicals quickly travel to the olfactory receptors in your nose. When your brain gets information from both the olfactory receptors and the taste buds, you experience the full flavor of what you are eating.
Question: According to the passage, what are the various receptors NOT responsible for?
(Multiple Choice)
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GMOs
GMOs, or genetically modified organisms, are organisms whose genes have been altered in laboratories. Scientists modify the genetic codes of plants or animals by inserting copies of desirable genes into the organism's DNA. While modifying organisms in a laboratory is a relatively new scientific development, people have been experimenting with genetics on plants and animals for centuries. For example, cattle ranchers have selectively bred their animals to produce cows that give more milk.
Although some people fear the "Frankenstein" nature of GMOs, there is no scientific evidence to suggest that GMO-based foods are harmful for human consumption. In fact, there are several reasons to believe that GMOs actually quite beneficial.
Through genetic modification, scientists can breed species of plants or animals that yield hardier, more abundant, or even more nutritious food. Geneticists have been able to produce rice plants that can survive droughts and wheat plants that are naturally pest-resistant. Some genetically modified foods have been engineered to have higher levels of specific nutrients, such as protein or calcium. Proponents of GMOs argue that these kinds of advances might one day help to end world hunger. Furthermore, genetically modified crops and animals can be bred to require fewer natural resources and produce less waste. This means that GMOs might also be better for the environment.
Question: Which of the following is NOT an advantage of genetically modified organisms?
(Multiple Choice)
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Antibiotic Resistance
Antibiotic resistance occurs when micro-organisms develop means of survival despite exposure to antibiotics. The development of antibiotic resistance can be traced to two main areas of antibiotic misuse: over-prescription by doctors and unnecessary introduction into animal feed by farmers.
The overuse of antibiotics by both doctors and farmers has increased antibiotic resistance by inadvertently fostering natural selection for resistance in colonies of bacteria. Bacteria that naturally carry antibiotic-resistant genes survive contact with the antibiotics. These resistant bacteria then reproduce, transferring their resistant genes to future generations of bacteria. Over time, this process yields a colony of bacteria that is fully resistant to antibiotics. Some bacteria even develop a variety of resistance genes; these bacteria are colloquially known as "superbugs" because of their ability to resist the majority of antibiotics. Staphylococcus aureus, the bacteria responsible for what is commonly known as a "Staph infection," is one of the most resistant pathogens. It is estimated that half of all Staph infections in the United States are resistant to penicillin, methicillin, tetracycline, and erythromycin-the four most common drugs used to treat such infections. The ever-increasing strength and population of these "superbugs" may pose a serious threat to human health in the near future.
The problem of antibiotic resistance has no easy solution. More funding should be available to scientists working toward the research and development of new antibiotics that will fight resistant bacteria. There are also steps that laypeople should take to help prevent further development of resistant bacteria. Individuals with viral infections should not demand antibiotics from their doctors. Consumers should also put pressure on meat manufacturers to stop adding unnecessary antibiotics into animals' diets. Finally, citizens should petition the government to increase funding for scientific research done to combat the growing problem of antibiotic resistance.
Question: What is the best meaning of the word colloquially in the phrase 'these bacteria are colloquially known as "superbugs"?
(Multiple Choice)
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The Pilomotor Reflex
Have you ever experienced the pilomotor reflex? Chances are that you have. The pilomotor reflex is actually something most people experience every day: goose bumps.
Goose bumps (also called goose flesh and goose pimples) are small bumps on the skin. They are created when tiny muscles beneath the hairs on your skin contract, pulling the hair into an upright position. They can occur anywhere that you have hair on your body, but they are most common on your arms and legs. Goose bumps are an involuntary reaction to many different sensations, such as cold, fear, or even happiness.
Humans are not the only animals that get goose bumps. When cats or dogs are threatened by an enemy, the pilomotor reflex will cause their fur to stand on end. This makes the animal look larger, which might scare away the enemy. Porcupines also experience the pilomotor reflex; a frightened porcupine will raise its quills when it is in danger. This not only makes the porcupine look bigger, it frightens enemies away by drawing attention to the sharp quills. The pilomotor reflex can also help animals stay warm by trapping body heat closer to their skin.
Because human beings have much less body hair than most other animals, goose bumps do not make us seem larger or more intimidating. They also do not help to keep us very warm, although they do help to prevent some heat from leaving the body. For the most part, the pilomotor reflex is much more important for animals than it is for people. In fact, many scientists think that the pilomotor reflex is actually completely useless for humans.
Question: What can we infer about an animal's ability to display the pilomotor reflex based on information presented in the passage?
(Multiple Choice)
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The Science of Taste
Have you ever looked at your tongue in a mirror? If so, you have probably noticed that it is bumpy. The bumps on your tongue are called papillae. Each one of the papillae contains hundreds of taste buds. You also have taste buds on the roof of your mouth and on your epiglottis, which is located at the top of your throat. The taste buds send messages to your brain that tell you about its basic flavor-that is, whether you are eating something salty, sweet, bitter, sour, or umami. Umami is hard to describe, but it is most often called a "meaty" or "savory" flavor. Foods with an umami flavor include meat broth, cheese, and soy sauce.
Your mouth and tongue also have receptors that send information about things besides the basic flavors of food. Your mouth has temperature receptor cells that can tell whether a food is piping hot or ice cold. Other receptors give information about the texture of food or how spicy it is.
But just being able to tell whether what you are eating is sour, cold, crunchy, or spicy is not truly tasting the food. For example, orange soda and root beer are both sweet, cold, and bubbly, but they do not taste the same. In order to get the full flavor of your food, you also need to use your sense of smell. The upper part of your nose contains special cells called olfactory receptors. They send messages about what things smell like to your brain. As you chew your food, chemicals quickly travel to the olfactory receptors in your nose. When your brain gets information from both the olfactory receptors and the taste buds, you experience the full flavor of what you are eating.
Question: What is a potential reason for including "Have you ever looked at your tongue in a mirror?" as the first sentence of the passage?
(Multiple Choice)
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Women in Clinical Trials
When new drugs or medical procedures are ready to be tested on human subjects, researchers find volunteers for clinical trials. However, far more men than women are used as subjects during these trials.
It was widely assumed for many years that women and men would respond to medication in the same way. Therefore, it did not seem to matter whether men or women were participating in clinical trials. Because of this, researchers mostly drew from pools of male volunteers because they were perceived to be more low-risk (and accordingly, less expensive to include in a trial). Women who are pregnant, nursing, post-menopausal or even simply of childbearing age are considered too "risky" to participate in clinical trials. These parameters essentially eliminate all women. However, it is difficult to determine whether this decision to eliminate women was made out of beneficence or paternalism.
The main problem with this gender discrepancy is that men and women are physiologically different. Their bodies process medications and respond to treatments differently. The over representation of men in clinical trials has impeded the progress of understanding how new medications will affect women.
Question: What is the best summary of the passage?
(Multiple Choice)
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Carbon Monoxide Poisoning
Carbon monoxide (CO) is a poisonous gas that has is odorless, colorless, and tasteless. These qualities make it possible for you to breathe in toxic amounts of carbon monoxide without realizing that you are in danger.
Carbon monoxide is produced when materials that contain carbon, such as wood, coal, gasoline, oil, or natural gas, are burned. If the space where the materials are burned is not ventilated properly, then the carbon monoxide that is released can build to dangerous levels.
Inhaling carbon monoxide causes the gas to build up in your bloodstream. CO molecules displace oxygen in your blood, depriving your heart, brain, and other organs of oxygen. Early signs of carbon monoxide poisoning include flu-like symptoms, such as dizziness, drowsiness, headache, blurred vision, nausea, and vomiting. Prolonged exposure to large amounts of CO can lead to unconsciousness, irreversible heart, lung, or brain damage, and death.
People who are most at risk of carbon monoxide poisoning include pregnant women, young children, the elderly, and people with serious heart or lung conditions. To prevent carbon monoxide poisoning, people should make sure that places where carbon-containing materials are burned are properly ventilated. Carbon monoxide detectors should also be present in homes, garages, and workspaces.
Which word would best replace the word 'displace,' found in paragraph 3?
(Multiple Choice)
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Diabetes
There are two types of diabetes: Type 1 and Type 2. Both types of diabetes can cause a variety of serious health risks if left untreated. Some of these health problems include kidney disease, blindness, heart disease, and strokes.
About 5-10% of people with diabetes have Type 1 diabetes. Type 1 diabetes most commonly develops in young people. In Type 1 diabetes, the immune system destroys the cells in the pancreas that secrete insulin. Without insulin, the body's cells cannot absorb glucose, and thus cannot produce energy. Symptoms appear after about 90% of the cells have been destroyed. Although most cases of Type 1 diabetes are genetic, some have arisen in people who have had viral infections of the pancreas.
Most people who have diabetes (90-95%) have type 2 diabetes, which most commonly develops in people over age 40. Type 2 diabetes results from the inability of tissues to respond to insulin-a condition called insulin resistance. As Type 2 diabetes progresses, the pancreas produces less and less insulin, resulting in a condition called insulin deficiency.
There is no cure for either Type 1 or Type 2 diabetes. However, there are ways to manage both types. For Type 1 diabetes, treatment requires receiving regular insulin injections. Type 2 diabetes can also be treated with insulin injections, but can be also be managed with lifestyle changes, such as weight loss, exercise, and reducing intake of carbohydrates.
According to the text, what can be inferred about a person with Type 2 diabetes?
(Multiple Choice)
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Balance
Everyone knows that your ears are responsible for your sense of hearing. But did you also know that your ears are also partially responsible for your sense of balance? Your inner ear contains something called the vestibular system, which is a key component in your body's ability to establish and maintain balance.
The vestibular system mainly consists of three semicircular canals. Each semicircular canal has a different orientation, allowing them to detect a variety of movements. The canals are filled with a fluid called endolymph. When you move your head, the fluid in the canals also moves; this movement sends signals to the brain about the position of your head. Your brain uses this information to help your body stay balanced.
Damage to the vestibular system caused by disease or injury can severely affect a person's balance. Consuming too much alcohol can also temporarily affect the vestibular system. Because alcohol thins the blood, it also changes the viscosity of the endolymph. The thinned-out endolymph sends signals to your brain that your body is rotating even though it is not. This is why many people feel like the room is spinning when they are drunk.
What is the primary purpose of this passage?
(Multiple Choice)
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The Science of Taste
Have you ever looked at your tongue in a mirror? If so, you have probably noticed that it is bumpy. The bumps on your tongue are called papillae. Each one of the papillae contains hundreds of taste buds. You also have taste buds on the roof of your mouth and on your epiglottis, which is located at the top of your throat. The taste buds send messages to your brain that tell you about its basic flavor-that is, whether you are eating something salty, sweet, bitter, sour, or umami. Umami is hard to describe, but it is most often called a "meaty" or "savory" flavor. Foods with an umami flavor include meat broth, cheese, and soy sauce.
Your mouth and tongue also have receptors that send information about things besides the basic flavors of food. Your mouth has temperature receptor cells that can tell whether a food is piping hot or ice cold. Other receptors give information about the texture of food or how spicy it is.
But just being able to tell whether what you are eating is sour, cold, crunchy, or spicy is not truly tasting the food. For example, orange soda and root beer are both sweet, cold, and bubbly, but they do not taste the same. In order to get the full flavor of your food, you also need to use your sense of smell. The upper part of your nose contains special cells called olfactory receptors. They send messages about what things smell like to your brain. As you chew your food, chemicals quickly travel to the olfactory receptors in your nose. When your brain gets information from both the olfactory receptors and the taste buds, you experience the full flavor of what you are eating.
Question: What is the primary purpose of this passage?
(Multiple Choice)
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Preventing Heart Disease
Heart disease is a life-threatening condition that kills millions of people every year. In fact, heart disease is the number one killer of human beings worldwide; over thirty percent of deaths every year are due to some form of cardiovascular disease. Although there are many different types of medications and surgical procedures that can treat heart disease, prevention is the most important factor in reducing the number of deaths.
Proper nutrition is important in preventing heart disease. The recommended diet for a healthy heart is low in saturated fats, cholesterol, salt, and refined sugar. The diet should be high in fiber, whole grains, fruits, and vegetables.
Smoking and excessive alcohol consumption should be avoided. Smoking increases the risk for heart disease at least ten-fold, and drinking too much alcohol can raise the levels of some fats in the blood and lead to high blood pressure and increase the risk of cardiovascular damage.
Lack of physical exercise can also make a person more likely to suffer from heart disease. Participating regularly in aerobic exercise, which can include walking, jogging, dancing, or swimming, significantly reduces the risk of heart disease.
Another contributor to heart disease is stress. Constant stress can expose your body to persistently elevated levels of the stress hormones cortisol and adrenaline. High levels of these hormones can increase blood pressure and damage artery walls. Engaging in yoga, meditation, or other relaxation techniques can be helpful in reducing stress and lowering the risk for heart disease.
Question: Which detail is included in the passage?
(Multiple Choice)
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Glowing in the Dark
Have you ever wondered how glow-in-the-dark things actually glow in the dark? Most glow-in-the-dark items glow because of something called phosphorescence or photoluminescence. Phosphorescent items must be "charged" under a bright light before they actually glow in the dark. This charging process works because of a substance called phosphor.
When light from the sun or a lamp hits phosphor, the phosphor molecules absorb the light and become energized. As the phosphor molecules release the stored energy, they emit a dim light that is visible in the dark. The color of the light that they produce depends on the color of the dye added to the glow-in-the-dark item. Usually, green dye is added to the phosphors to make the light easier to see. Although any color can be used, the human eye sees green light most clearly in the dark.
There are also a few glow-in-the-dark items that do not need to be charged. Emergency exit signs, gun sights, and certain kinds of expensive wristwatches glow because of radioluminescence. In these items, the phosphor is mixed with a radioactive element called tritium. The radiation from the tritium provides energy to the phosphor. It is almost as if there are thousands of tiny lamps constantly shining on the phosphor. Because their phosphor is always energized, these radioluminescent items are always glowing.
One other kind of glow-in-the-dark item that does not require charging is the glow stick. Glow sticks do not need to be held under light and do not contain any radioactive elements. Instead, glow sticks glow using chemiluminescence. Glow sticks contain a fluorescent dye and a thin glass tube that contains a chemical. To activate a glow stick, you bend the plastic container, causing the glass to break. The chemical inside the glass then mixes with the dye. The combination of the chemical and the dye produces visible light.
Question: What is the meaning of the word energized in the passage?
(Multiple Choice)
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