Vitamin C for a cold? A good dose of Vitamin D on a sunny day? We all know that vitamins are critical for our health, but how did they get their names and when were they discovered in the first place?
American nutrition scientist Elmer McCullum conducted a variety of feed experiments with different animal populations and discovered that an “accessory” substance contained in some fats was essential to growth. That fat-soluble (脂溶的) substance became known as Vitamin “A” for “accessory.”
McCollum and others also conducted further experiments with rice-bran-derived nutrient, naming it Vitamin “B” after beriberi, which can cause heart failure and a loss of sensation in the legs and feet. Eventually, it turned out that the substance known as Vitamin B was a complex of eight water-soluble vitamins, which were each given individual names and numbered in order of discovery.
The custom of naming vitamins alphabetically in order of discovery continued. Today, four fat-soluble vitamins (A, D, E, and K) and nine water-soluble vitamins (Vitamin C and the eight B vitamins) are considered essential to human growth and health. Only one vitamin bucked the oh-so-logical naming system: Vitamin K, discovered by Danish researcher Carl Peter Henrik Dam in 1929. The substance should have been in line to be called Vitamin F given its discovery date. But Dam’s research revealed that the vitamin is essential for blood coagulation (凝固) — known as Koagulation in the German journal that published his research — and his abbreviation for the vitamin somehow stuck.
It’s been decades since the last essential vitamin — Vitamin B12 — was discovered in 1948. It now appears unlikely that scientists will ever discover a new essential vitamin. But even if there’s no Vitamin F or G in our future, that doesn’t mean nutritional discovery has stopped completely. If the golden age of vitamin discovery was an appetizer (开胃菜) of sorts, scientists are devoted to the main course — a rapidly evolving understanding of the ways food shapes our lives, one microscopic substance at a time.
1. What can we learn from paragraph 2 and paragraph 3?| A．Vitamin A is a water-soluble substance. |
| B．Vitamin B was named after a kind of disease. |
| C．The eight B vitamins got names from their functions. |
| D．The subjects of McCullum’s experiments are home. |
| A．Created. | B．Destroyed. | C．Broke. | D．Followed. |
| A．Indifferent. | B．Unclear. | C．Doubtful. | D．Confident. |
| A．How Do Vitamins Influence Our Health? |
| B．Who Discovered Various Vitamins for Us? |
| C．Why Is There a Vitamin K but No Vitamin F? |
| D．How Many Vitamins Are Still Left to Be Discovered? |
相似题推荐
【推荐1】In summer the extreme heat often makes people sweaty and restless. While people are annoyed by it, experts suggest summer is the best season to discharge(排放) your body’s toxins(毒素) and recover your energy.
One popular option is hot-stone massage(按摩). Therapists use smooth and heated stones, usually river rocks, to massage certain parts of the body, or place them on key points of the body. The warmth of the hot stones will improve blood circulation and also help relax muscles, while sweating is also believed to be good for discharging the body’s toxins.
Another popular option is hot-stone baths. The hot-stone bath will help the body discharge toxins and humidity(湿气) that accumulated during the last winter. Summer is the best season to build a good body. Rather than use water or steam to heat and wash the body, people simply wear a coat or something comfortable, and then lie on heated stone tablets made of hot stones, which are warmed to around 45oC. The body will gradually warm up and blood circulation will also be improved. More sweat will come out quickly. The sweat is smooth and fresh, not smelly like that released after sports activities. Such baths bring a number of health benefits, such as anti-aging, improved blood circulation and stress relief. The slimming effect of dieting can even be promoted.
Using hot stones for healing dates back to ancient times, but the modern renewal of hot-stone massage is generally credited to Mary Nelson, a native of Tucson, Arizona, America, whose trademark is “LaStone Therapy”.
The therapy is gaining wide popularity with many people, especially those who have jobs in cool air-conditioned rooms. The hot-stone therapy can help cure many diseases, including back pain.
1. What do people use to release toxins in our body according to the text?| A．Swimming in white water. | B．Living in cold winter. |
| C．Lying on the warm beds. | D．Discharging lots of sweat. |
| A．People should take advantage of summer to improve their health. |
| B．There are no toxins and humidity in the body in summer. |
| C．Using water of about 45oC to wash the body is good for the health. |
| D．Sports have greater effects on the health than hot-stone massage. |
| A．It was invented by Mary Nelson, an American. |
| B．It successfully cured many people of cancer. |
| C．It is popular with people because of its excellent effects. |
| D．It can help people avoid sweating too much in hot summer. |
| A．The origin and development of the hot-stone therapy |
| B．A healthy and comfortable lifestyle |
| C．How to live comfortably in summer |
| D．The amazing functions of the hot-stone therapy |
【推荐2】If you’ve watched Grey’s Anatomy, then you’ve gotten an insight into the complex hierarchies (等级) that rule a hospital. Over 17 seasons, the show’s heroine, Meredith Grey, got promoted from a lowly intern (实习生) to chief of general surgery, learning from the presiding residents and older surgeons along the way. There’s rarely doubt about who is in charge, who has more expertise, or who should be supervising and training other staff. Grey’s fictional journey illustrates the complicated dynamics of a health care setting, whether it’s a local clinic or a busy city hospital. Those hierarchies can help teams provide care efficiently, but what happens when those traditional roles are disrupted?
“These status barriers are tricky,” says Sara Singer, a professor of organizational behavior and a professor of medicine.“They can get in the way of medical professionals learning new skills, particularly when junior employees are asked to show more senior coworkers how to use a new technology. ” But, as Singer and her coauthors reveal in a recent paper, upending these complex hierarchies can be a useful training strategy.
Singer and her coauthors studied observations from five different primary care settings over the course of nearly two years. At each, medical assistants and patient-service representatives had to learn several new digital technologies. Even though these positions are fairly low in the medical and administrative order, Singer says that within these jobs, tenure and status are still important. So when younger employees were selected to be trainers, that threw the typical power balance off the good state. At some sites, employees struggled to pick up the skills they needed. “There were some groups where the training seemed to be taking and people seemed to be following on with the work that was intended,” Singer says. “But at other places it just wasn’t working out.”
By creating a system that gave everyone a chance at those opportunities, clinics could remove the jealousy that might come from selecting one younger employee over another time and time again.
1. Why is Grey’s Anatomy mentioned in the text?| A．To review the main heroine. | B．To introduce the main topic. |
| C．To tell readers a new movie. | D．To show the author’s attitude. |
| A．The status barriers in existence. |
| B．The way to provide care efficiently. |
| C．The learning spirits of a new employee. |
| D．The traditional managing system of medical institutions. |
| A．Hospitals should offer equal opportunities to accept training. |
| B．Newly-employed medical workers work hard to learn skills. |
| C．It is challenging to change the conventional training approach. |
| D．A new system should be created to evaluate doctors and nurses. |
| A．Younger colleagues can be trained to teach older workers new skills. |
| B．Health care settings in the world are extremely complex. |
| C．Everybody likes to give the younger people instructions. |
| D．Medical residents are too busy to balance their work and life. |
【推荐3】It is not just doctors and nurses that work at Children' s National Hospital in Michigan. There are also two furry friends on the staff.
Their main responsibility is to comfort the young patients at the hospital. Their work called animal-assisted therapy.
Facility dogs are expertly trained dogs who partner with a facilitator working in a health care, visitation or education setting. They would visit kids for a hug or paw shake. More than just dogs can be animal therapists.
This year, for safety reasons, the hospital had to pause the animal therapy program. But Allison Proctor still runs her program.
| A．The program focuses on a medical goal |
| B．Small horses would sometimes hang out |
| C．Each has an important job as a facility dog |
| D．It is known to have many positive effects on patients |
| E．These animals usually have to go through special training |
| F．Each team had one dog, plus one human in charge of the dog |
| G．Her commitment to the treatment with the human-animal bond never stops |
【推荐1】Wood from a tree that has just been cut down will shrink (收缩) considerably over time. This shrinkage is caused by water within the wood escaping into the atmosphere. The drying process of wood is known as “seasoning”. There are actually two ways to season wood. One way is to allow the natural drying process to occur. The other is to put it in a special oven called a kiln.
During the seasoning process, water is removed from the wood until the water content of the wood is approximately equal to the moisture (湿度) of the air around it. These changes in size due to shrinkage are not uniform. They depend on the kinds of trees, the way trees are cut, and the surrounding conditions.
Even after seasoning, there will always be some small changes in size due to changes in the moisture of the surrounding air. For example, last year I used a 230 mm wide piece of eastern white pine wood to make a door. It changed in width across the grain (花纹), shrinking by 2 mm from the original in the winter and expanding by 3 mm from the original in the summer.
The water content of wood changes according to the seasons even when it is kept indoors. Wood is often painted to prevent sharp changes in moisture content, which cause expansion and shrinkage. However, no paint can completely block the passage of moisture. It only acts to slow down the transfer of water to or from the wood. The moisture content of unpainted wood inside a house may change according to the seasons from 4% to about 14%, while the moisture content of a painted piece of kiln- dried wood in the same house will only vary around the 8% line. Wood that has been naturally dried to around 13% moisture content and then painted will continue to dry gradually until it reaches about the same percentage of moisture as painted kiln-dried wood.
1. What does the underlined word “uniform” mean in Paragraph 2?| A．Identical. | B．Visible. | C．Measurable. | D．Concrete. |
| A．1 mm. | B．2 mm. | C．3 mm. | D．5 mm. |
| A．Wood can be “seasoned” by painting it. |
| B．Kiln-dried wood does not later change size. |
| C．The moisture content of wood changes outdoors. |
| D．Painted wood stays away from expansion and shrinkage. |
| A．The changes of water content in wood varies. |
| B．Painted wood is free from shrinkage. |
| C．Painting wood is not an effective way. |
| D．Water transfers more slowly in painted wood. |
【推荐2】It is reported that using a smartphone at mealtimes can lead to an expanding waistline. Researchers have found that men and women consumed 15 percent more calories when looking at their phones while eating. They also ate more fatty food. The groundbreaking study suggests that staring at a phone screen may distract diners from how much food they are actually eating.
"It may prevent the correct understanding of the brain over the amount of food that is eaten," said researchers who filmed 62 volunteers eating alone.
The men and women, aged from 18 to 28, were invited to help themselves to a choice of food 一 ranging from healthy options to soft drinks and chocolates - until they were finally satisfied. In three trials, the volunteers were recorded eating with no distractions, using a smart phone or reading a magazine. According to the study, on average, the volunteers ate 535 calories without the distraction of a smartphone but 591 calories when using a mobile phone instead.
Those in the sample who were classified as overweight ate 616 calories while using their phones. When they were in possession of their mobile phones, the volunteers consumed 10 percent more fatty foods. When reading a magazine, they also ate more compared with no distractions during a meal, but they consume less calories compared with the use of smart phones when having a meal.
"The use of a smart phone during a meal increased calorie and fat intake," said Marcio Gilberto Zangeronimoa, a lead author of the study carried out at the Federal University of Lavras in Brazil and University Medical Center Utrecht in the Netherlands.
He added, "At present, tablets and smart phones have become the main 'distractors' during meals, even early in childhood, and distractors prevent the brain correctly understanding the amount of food ingested, so it is important to pay attention to how this may impact food choices."
1. Which phrase can best replace the underlined word "distract" in the first paragraph?| A．Draw ... to ... | B．Give ... out. |
| C．Bring about... | D．Break ... up. |
| A．eating with no distractions | B．eating with a magazine |
| C．eating with a phone | D．eating with a tablet |
| A．Favorable. | B．Negative. | C．Indifferent. | D．Surprised. |
| A．a diary | B．a magazine | C．a novel | D．a tourist guide |
【推荐3】Fever has usually been regarded as a threat to health. However, no one has actually proved that fever is dangerous. This fact attracted the attention of Matthew J. Kluger. Imagining that fever might not be as harmful as it had been supposed, Kluger set up a series of experiments with lizards (蜥蜴).
What Kluger and his team did in their first experiment was simple. They put some lizards in a sand-box, one end of which was heated to 44°C, while the other was at a room temperature. It was found that the lizards moved from one part of the box to the other in order to keep a constant temperature of about 38°C. Having shown that normal lizards regulate (调节) their own temperature, Kluger, in a second experiment, then set out to show that lizards, like most other animals, develop fever when infected (感染). This was done by making lizards infected with bacteria (细菌) that were known to cause disease. As the team expected, the infected lizards remained longer in the heated part of the box, until they had raised their body temperatures to two or three degrees above normal. In other words, the sick lizards gave themselves fever.
In a third experiment, the team observed the effect of temperature on the survival of the lizards. One group of infected lizards was given a fever-suppressing (退烧) drug. The other group was given no drug and ran a fever, that is to say, they kept a higher temperature for four or five days before seeking a cooler environment. The results were impressive. Of those which raised their body temperature, all but one remained alive. Of those given the fever-suppressing drug, more than half died. Similar results have since been produced in other animals. For example, infected fish swim to warmer water, and will die if not allowed to do so.
An important conclusion can be drawn from these experiments. As Kluger points out, lizards have been on earth for hundreds of millions of years. It is reasonable to suppose that a response that is so old has been kept by nature for some purpose. It would appear, therefore, that fever does not make disease worse. Rather it is part of the mechanism (机能) by which infection is controlled.
1. In his experiments, Kluger was hoping to prove that fever ______.| A．is not harmful to lizards |
| B．is necessary for both humans and animals |
| C．is not necessarily bad |
| D．has the same effect on humans and animals |
| A．they had no more fever that they needed |
| B．they were normal ones and had no fever |
| C．the drug had no effect on sick lizards |
| D．the drug made their body temperature too low |
| A．Recovery from disease |
| B．Natural defense in the body against disease. |
| C．Cause of disease. |
| D．Relationship between living things and nature. |
| A．Lizards are most suitable for experiments on fever. |
| B．Fever may play an important part in curing disease. |
| C．Fever helps lizards to get rid of infection. |
| D．Lizards and humans are not as different as people supposed. |
【推荐1】As people are becoming more socially concerned about where their food comes from and how it impacts the planet, they are choosing animal-free plant-based options. Cow-free meat has been around for quite some time and the popularity of brands of the cultivated (培育的) meat is rising. While there are a large number of plant-based milk substitutes (替代品), none of them have the same taste of cow’s milk. Now, a food-tech company created real dairy products (奶制品) without harming a single cow or the planet.
The company stresses that their product produced in the lab is not a milk substitute but rather is the real deal. And it is very healthy. The company also says that the lab-produced milk tastes the same as the real thing and they hope to eventually replace cows by creating every dairy product sold. They expect to roll out plant-based cheese and yogurt in addition to milk. “ Our company was founded with the mission to stop using animals to produce our food because, as dairy lovers, we realize that giving up on milk is not a choice, ” John said. “ But today’s milk comes with an unreasonable environmental price tag. The dairy industry is destroying our planet, our health, and our animals, and is simply not sustainable (可持续的) anymore. ”
The environmental price tag of dairy farming is too high. According to the World Wildlife Fund, dairy cows add a huge amount of greenhouse gases to the atmosphere and contribute to global warming and climate change as well as pollute the air around them. Dairy operations consume large amounts of water and run-off of manure (粪肥) and fertilizers from these farms get into local waterways. The production uses only 5 percent of the resources and produces only 1 percent of the waste of producing cow’s milk according to the company. And they accomplish this by being 100 percent cruelty-free unlike dairy farms.
1. The food-tech company’s milk mentioned in the text is different from other milk substitutes ________ .| A．its various plant-based tastes | B．it tastes the same as cow’s milk |
| C．its highest output from the farms | D．its broad popularity home and abroad |
| A．Prices of cow’s milk are rising these days. |
| B．All the destructive dairy industries should be closed. |
| C．The food-tech company was set up for animal protection. |
| D．The food-tech company aims to produce animal-free food. |
| A．Dairy cows. | B．Dairy operations. | C．Climate changes. | D．Greenhouse gases. |
| A．Healthier Milk. | B．New Milk Saves Planet. |
| C．Fresher Milk, Better Future. | D．Making Milk without Cows. |
【推荐2】Anything made of plastic or metal can be 3D printed nowadays — bicycles, toys, tools... even replacement body parts! But the latest trend in 3D printing may be food. Scientists and chefs are putting their heads together to create printed food.
Several 3D printers designed for food are now on the market. Anything that can be made into a soft wet mixture can be squeezed (挤压) from a tube in a 3D printer. Instead of ink, these printers can use fruits, vegetables, proteins, sweets, and more. This makes for lots of combinations that can be healthy, yummy, and even artistic.
Most 3D printers don’t actually cook the food, at least not yet. Engineers at Columbia University’s Creative Machines Lab invented an oven (烤箱) that cooks 3D-printed pizza with laser beams (激光束). A special computer program controls the lasers, heating each part of the pizza to perfection. Unlike regular ovens, lasers can carefully cook each thin piece of 3D-printed food.
In the future, food can be made with a 3D printer to meet our needs. For example, a hospital could design meals to meet patients’ dietary needs. Vitamins, minerals, and even medicines can be mixed right in. A 3D printer can make food appealing. Foods that someone may not like might be more attractive after 3D printing. Maybe that food you dislike wouldn’t seem so bad if it looked like a castle!
The idea of 3D printed food may seem very modern. In fact, NASA (美国国家航空航天局) has been researching the topic for more than ten years. On a long travel, it’s important to have food that is easy to make, tastes good, and has the nutrients astronauts need to stay healthy. Printing food on demand may soon be into the space!
1. What will be the latest trend in 3D printing?| A．3D printed bicycles. |
| B．3D-printed toys. |
| C．3D-printed food. |
| D．3D-printed body parts. |
| A．It is invented by students at Columbia University. |
| B．It is made from strong laser beams. |
| C．It can make 3D-printed food carefully. |
| D．It can cook each part of 3D printed food perfectly. |
| A．Attractive. |
| B．Fresh. |
| C．Healthy. |
| D．Terrible. |
| A．Anything Can Be 3D Printed |
| B．3D Printing: the Future of Food |
| C．NASA’s New Research |
| D．How to Cook 3D Printed Pizza |
【推荐3】Is there anybody out there? For centuries humans have wondered, although the ways in which we have gone about this have varied. As we have gained a greater understanding of the universe, our searches have taken on more concrete forms. Questions about aliens(外星人) have become a subject for science rather than science fiction.
Now new cooperation between the Very Large Array (VLA) observatory in New Mexico and the SETI Institute in California means that our curiosity about aliens can be closer than ever before to being satisfied. Data from the VLA’s 28 radio telescopes, used to scan a vast area of sky, will be fed through a special supercomputer that will search for distant signals.
How likely it is that a signal will be found, and what this might mean, are hard questions to answer. SETI’s existing projects have not detected any signals from other planets so far. But recent discoveries in space and Earth sciences have provided some encouragement for those who are enthusiastic about the possibility, however remote, of detecting other civilizations.
Once it was thought that our solar system could be unique. Since the discovery of the first exoplanet (a planet beyond the solar system) in the 1990s, thousands more have been located. Around one in five stars is now thought to have a planet in their orbit in a so-called ”habitable(适合居住的) zone”— that is, at a distance from the star where the temperature means that life is theoretically possible.
Are Earth’s 7.5 billion humans, along with billions of other animals and plants they share their home with, on their own in the universe? If there is another life form somewhere, could it be as intelligent as humans? Or could it threaten them? I think all of these need further exploration. As explorations of Mars continue, and a new set of observations from the James Webb Space Telescope are set to begin, our interest in the possibility of alien life appears as much as before.
1. Why does the VLA work with SETI?| A．To develop new radio telescopes. | B．To satisfy some people’s curiosity. |
| C．To build a special supercomputer. | D．To find evidence of aliens’ existence. |
| A．Some exoplanets may have habitable zones. |
| B．New technologies are adopted to find aliens. |
| C．Signals have been detected from other planets. |
| D．Life does indeed exist on exoplanets. |
| A．Positive. | B．Uncertain. | C．Worried. | D．Unacceptable. |
| A．Exoplanets: home of aliens | B．Receiving signals:aliens appear again? |
| C．Finding aliens:possible or not? | D．Space: the unknown place |
