There’s a lot we know about eggs: they are great for breakfast and you can cook them in different ways. One topic of debate, however, is why brown chicken eggs usually cost more than white ones. According to Shaman Hickman, the director of Community Outreach and Education for Hickman's Family Farms, genetics (基因学) not nutrition determines the eggshell colour and thus the egg’s price.
The chicken breed (品种) and their genetics decide whether or not hens have pigment (色素) genes, which coat the egg and result in a coloured shell during the egg-laying process. Although all eggs start out white in colour, shell colour can range from white to brown and even blue in some rare breeds, Hickman adds. Breeds such as the Leghorn chicken lay white eggs, while the Orpington lays brown eggs and the Ameraucana produces blue eggs.
Hickman notes that the Leghorn breed is the most efficient egg-laying hen, making it a popular choice for farmers. Hens that produce coloured eggshells, however, tend to be larger and require more feed and energy to create that painted layer. Since those breeds cost more to feed, their eggs are more expensive.
Although eggs sometimes look different and are priced differently, it’s impossible to know their nutritional make-up from the shell colour alone, according to Malkani, media spokesperson for the Academy of Nutrition and Dietetics. “Choosing between brown and white eggs is a matter of personal preference,” she says. “But it's important for people to know that the colour of the eggshell has nothing to do with the egg’s nutrient content or shell thickness.”
What does affect the nutrient content is the specific diet the hen is on, according to Malkani. For example, hens fed with a diet with omega-3s and vitamin D produce eggs that are higher in those specific nutrients. No matter what your preference is, don’t judge an egg by its shell colour.
1. Which of the following is one of the arguments about eggs in Paragraph One?| A．Why Brown eggs are much cheaper. | B．How eggs can be cooked healthily. |
| C．Why coloured eggs are more expensive. | D．Whether brown eggs are great for breakfast. |
| A．The size of the hen. | B．The hen’s breed. |
| C．The colour of the eggs inside. | D．The environment of the laying process. |
| A．They are productive. | B．Their eggs are larger. |
| C．They lay brown eggs. | D．Their eggs sell better. |
| A．It takes efforts to test eggs’ nutrition. |
| B．It’s meaningless to study an egg’s colour. |
| C．Personal preference matters a lot in choice-making. |
| D．An egg's nutrition is closely related to the hen’s feed. |
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【推荐1】Man’s best friend is also his oldest. The partnership between dogs and people may go back as much as 40,000 years long predating any other domestication （驯化）. And it is based not, as is the case with many succeeding domestications, on a human desire to eat the animal concerned, or to consume some associated product such as milk or eggs, but rather on sincere companionship, though with a little work — and hunting-related using on the side.
How this partnership got going, though, is debated. In particular, unlike other domestications, which involved groups of people who had taken up farming, the domestication of the wolves that became dogs happened while all human beings were still hunter-gatherers. The two species were, in other words, competitors. Yet they managed to become soul mates.
One popular theory is that the wolves which became dogs acted as rubbish cleaners for groups of people, by eating their waste, possibly including their faeces （粪 便）.That, though, would be a service more useful to settled farmers than mobile hunter-gatherers. As she writes in Scientific Reports, however, Maria Lahtinen of the Finnish Museum of Natural History thinks she might have the answer as to how wolves and people squared the competitive circle while both species were still hunters. It was, she and her colleagues suggest, simply a matter of remaining calories.
The archaeological （考古的）evidence suggests that wolves were domesticated in wood lands at the edge of the ice sheets of the last ice age, since that is where almost all Palaeolithic dog remains have been found. Dr Lahtinen calculates that, given the large size of hunted animals in this environment, and humans' need to eat a balanced diet with plenty of plant matter in it as well as flesh, there would have been a lot of remaining meat around from kills. What better way to use some of it than to feed a few wolf cubs （幼崽）to provide entertainment and companionship? And thus, she suggests, were dogs born.
1. Why did our ancestors domesticate dogs?| A．To balance their diet. | B．To help them to farm. |
| C．To get rid of rubbish. | D．To develop a partnership. |
| A．Dogs were born as early as wolves. |
| B．People ever hunted wolves for food. |
| C．Wolf cubs were raised for remaining meat. |
| D．Cruel enemies could become good friends. |
| A．A new idea. | B．Some evidence. |
| C．A practical way. | D．A scientific report. |
| A．Home & Life. | B．Finance & Economy. |
| C．History & Future. | D．Science & Technology. |
【推荐2】Recently, Australian scientists tried a new tracker on the magpies. They hoped to learn more about how far the birds flew and what they did during a normal day. The scientists are concerned that magpies may have a hard time adjusting as the world warms up because of climate change.
Australian magpies are medium-sized black and white birds. They live in groups of up to 12 birds and work together to defend the area they live in. It’s hard to find trackers that work well with small and medium-sized birds. But the newly-produced trackers were light enough and could be recharged without wires while they were still on the birds. To keep the trackers on the birds without causing flying problems, the researchers developed a special harness. It was tough, so it wouldn’t come off by accident. But it had a special release controlled by magnets, which allows the scientists to free the birds from the harnesses at a special magnetic bird feeder, without having to catch the birds again.
The researchers placed trackers on five magpies using their special harnesses. But just ten minutes after setting up the last magpie, they noticed something unusual: An adult female magpie was helping another magpie get free from its harness. In a few hours, most of the other magpies were also freed from their harnesses. By the third day, none of the birds had trackers anymore.
The scientists were disappointed about the trackers, but they realized that the magpies had taught them something else — that magpies are able and willing to help each other out, even if the bird who is helping doesn’t get a reward. This is called “rescue behavior”, and it’s not that common in the animal world, especially among birds. The researchers think this is the first time rescue behavior has been reported for Australian magpies.
The researchers are glad they’ve learned about the rescue behavior of magpies. But now they need to try again to figure out a good way to track these clever birds.
1. Why did researchers attach trackers to magpies?| A．To learn more about magpies’ habits. | B．To help them identify magpies clearly. |
| C．To precisely monitor magpies’flying route. | D．To further explain what rescue behavior is. |
| A．Feather. | B．Tracker. | C．Belt. | D．Recorder. |
| A．Friendly but noisy. | B．Cute but unhelpful. |
| C．Brave and playful. | D．Smart and cooperative. |
| A．Climate Change Has Affected Magpies Badly |
| B．Magpies Teach Scientists an Unexpected Lesson |
| C．Researchers’ Understanding of Rescue Behavior |
| D．Findings About New Trackers on Australian Magpies |
【推荐3】Many animals climb, but few do it as well as the spiders. These eight-legged creatures can be anywhere. Now researchers have come up with surprising clues as to how spiders can stick to almost any surface. The structure of tiny hairs at the tips of the spiders’ legs likely help them hang on.
Clemens Schaber, who led the new study, said, “Adhesion, or stickiness, is an important part of that. Spiders don’t have a sticky liquid on their feet. Instead, they use ‘dry’ adhesion. Animals that use dry adhesion can stick and unstick to surfaces easily.”
At the end of a spider’s leg, there are some so-called hairs. At the tips of these hairs are small, flat structures that look like spatulas. When the hairs touch something, these “spatulas” form bonds with the surface and stick. Before this latest research, Schaber knew the hairs were important for adhesion. He wanted to know more about why they worked so well.
They first tried to pull the hairs off the spider legs. But the whole leg often came off. This is a natural defense that the spiders use to escape their enemies. Then they used a powerful microscope to view the hairs up-close. Schaber expected that all the hairs would point in the same direction, more or less. But it wasn’t like that. Instead, as the researchers looked at the tip up-close, they saw the ends of the hairs were all a little bit different in direction.
The researchers then tested the stickiness of the hairs on different materials. They found that some hairs had the strongest adhesion at one angle. Others worked best at other angles. So this mix of angles and adhesions may help the spider stick no matter how it touches a wall.
“The study is quite interesting,” said Schaber. “It shows us new ways to think about making structures stick to surfaces.”
1. What did the researchers find in the study?| A．Spiders’ motivation to climb. | B．Spiders’ sticky liquid on their feet. |
| C．The secret to spiders’ ability to stick. | D．The existence of hairs on a spider’ s legs. |
| A．The real purpose of the study. | B．The shapes of so-called hairs. |
| C．The stickiness level of so-called hairs. | D．The link between surface and stickiness. |
| A．The shape of spatulas. | B．The number of tiny hairs. |
| C．The direction of tiny hairs. | D．The importance of tiny hairs. |
| A．It shows us new ways to study animals. | B．It gives humans more creative ideas. |
| C．It proves humans can climb as spiders. | D．It helps to find a naturally sticky material. |
【推荐1】The riches of the natural world aren’t spread evenly across the globe. Places like the tropical Andes (赤道安第斯山脉) in South America are packed with unique species, no place else to be found on Earth. Previously, the main explanation for the biological riches concentrated in places like the Amazon Basin was that they were such places where new species evolved at a faster rate than other parts of the world. But now, new research on bird evolution may turn that assumption on its head. Instead, it supports the idea that areas with fewer species actually tend to produce new species faster.
The researchers say the biodiversity cold spots are generally found in harsher (更严酷的) environments featuring freezing, dry and unstable conditions. Though the researchers have found these locations with few bird species tend to produce new ones at high rates, they fail to accumulate many species because the unstable conditions frequently make the new life forms die out.
The more well-known hot spots, by contrast, have accumulated their large numbers of species by being warm, hospitable and relatively stable. Indeed, the researchers have found that the countless bird species that call the Amazon home tend to be older in evolutionary terms. That actually accounts for higher species richness there.
“Our results suggest that these hots pots for biodiversity are not hot spots for the evolution of new species,” says Elizabeth Derryberry, an evolutionary biologist at the University of Tennessee. “New species do form in places like the Amazon, just not as frequently as in more extreme environments.”
The researchers managed to collect 1,940 samples (样本) representing 1,287 of the 1,306 bird species from South America. Their analysis revealed that the best predictor of whether an area would produce new species at a high rate was how many species lived there, rather than climate or geographic features like mountains. Species rich areas tended to produce new species more slowly.
On a practical level, the study’s findings add new urgency for stopping destroying ecosystems that may look dry and bare, because they may actually be nature’s hothouses for the evolution of new species.
1. What is the previous explanation for biodiversity in the Amazon Basin?| A．Its species’ strong survival abilities. |
| B．The immigration of foreign species. |
| C．The rapid evolution of new species. |
| D．Its vast living space for new species. |
| A．There’s less competition and more chances. |
| B．It constantly attracts new species to come. |
| C．It had extreme environments a long time ago. |
| D．The environment there is stable and favorable. |
| A．protect harsh ecosystems |
| B．help species in hot areas live longer |
| C．develop species-rich environments |
| D．limit species in biodiversity cold spots |
| A．Bird species prefer to live in harsher ecosystems. |
| B．Species poor areas may produce new species faster. |
| C．Tropical areas are home to large numbers of species. |
| D．Hot areas are more attractive to species than cold areas. |
【推荐2】The next time someone asks you where the biggest ocean is, point them toward Jupiter. While earth harbours about 320 million cubic miles(1,333 cubic km)of water, our planet is practically a desert compared to the rest of the Solar System.
A moon of Jupiter called Europa, for example, which is roughly the size of our own Moon, likely hides a subsurface ocean with more than twice as much water as there is on Earth.
Yet even that pales into insignificance in comparison to Europa's neighbour Ganymede; more than 30 times as much water as our home planet is thought to reside there as liquid and ice.
And scientists keep finding more water wherever they look. On September 28, researchers reported that Dione — a small moon of Saturn — probably has a subsurface ocean, too.
To see just how Earth stacks up against other ocean worlds, Business Insider contacted Steve Vance, a planetary scientist at NASA's Jet Propulsion Laboratory who's calculated the numbers on just how much water might be out there.
In order of how much water they have, from the least to the most, they are: Enceladus, Dione, Earth, Europa, Pluto, Triton, Callisto, Titan, and Ganymede. Mimas, a moon of Saturn, and Ceres, the largest asteroid in the Solar System, are also thought to have subsurface oceans —but scientists aren't yet sure how big each one might be.
1. How many stars are mentioned in this passage?| A．Eleven. | B．Twelve. |
| C．Thirteen. | D．Fourteen. |
| A．Compared with the Solar System, Jupiter looks as if it is a desert. |
| B．Ganymede is thought to be covered with more water than Europa. |
| C．Business Insider is a planetary NASA’s laboratory of Steve Vance. |
| D．Ceres harbours the largest subsurface ocean in the Solar System. |
| A．The order of how much water the stars have has been figured out. |
| B．Scientists keep exploring more water in the universe wherever they look. |
| C．These ocean worlds reveal just how little water we have on Earth. |
| D．NASA’s planetary scientists are calculating the water numbers in the sky. |
【推荐3】Facial images can be used to identify signs of disease in diagnosis (诊断). For example, abnormal changes in eye movement can indicate poor visual function and visual developmental problems. However, facial images also record other information about the patients, including their race, sex, age and mood. Due to privacy concerns, people often hesitate to share their facial images for public medical research or electronic health records, blocking the development of digital medical care.
The researchers now develop a digital mask, which inputs an original video of a patient’s face and outputs a video based on the use of a deep learning algorithm (算法)and 3D reconstruction. At the same time, the digital mask can remove as much of the patient’s personal biometric (生物统计的)information as possible.
Next, the researchers tested how useful the masks were in clinical practice and found that diagnosis through the digital masks agrees with that carried out through the original videos. This suggested that the technology was accurate enough in clinical practice. The team also confirmed that the digital masks can also avoid artificial intelligence-powered facial recognition.
The team surveyed randomly (随机地)selected patients attending clinics to test their attitudes towards digital masks. Over 80% of patients believed the digital masks would ease their privacy concerns and they expressed an increased willingness to share their personal information if such a measure was carried out.
Professor Patrick from the University of Cambridge said, “Digital masks offer a practical approach to protecting information from facial images, while still allowing the information to be useful to clinicians.” This could make telemedicine-phone and video consultations, much more practicable, making healthcare delivery more efficient especially during the COVID-19 pandemic. If tele-medicine is to be widely adopted, then we need to overcome the barriers and concerns related to privacy protection. The digital mask is an important step in this direction.
1. What is the problem with the facial images in diagnosis?| A．Its result may be inaccurate. |
| B．Its process is too complicated. |
| C．It may reveal patients’ privacy. |
| D．It fails to observe eye movement. |
| A．It preserves biometric information of patients. |
| B．It can prevent the individual being identified. |
| C．It has high requirements for the original videos. |
| D．It helps doctors diagnose disease more accurately. |
| A．Objective. |
| B．Cautious. |
| C．Critical. |
| D．Supportive. |
| A．The significance of the digital mask. |
| B．The future development of telemedicine. |
| C．The barriers to protecting patients’ privacy. |
| D．The practical ways to protect patients’ privacy. |
【推荐1】We are all familiar with that little excitement from creating a popular post on Facebook. Watching the number of likes can be both attractive and addictive.
That same buzz (兴奋) can have its disadvantages, though. We all know the feeling of watching other people’s posts get unending positive feedback. We tell ourselves that the only reason why these people are getting attention is that they’re popular and good-looking. We sink into self-loading (自我讨厌) and comparison. Therefore, after experimenting with hiding likes on Instagram in select countries, Facebook is exploring doing the same on its main platform.
That Facebook is considering this is encouraging. After years of appearing to ignore criticism about its effects on society, the company finally seems to be listening. However, there is a basic conflict between Facebook’s business model and its new-found altruism (利己主义). Relying on Facebook to look after its users’ mental health is a bit like asking McDonald’s to keep its customers’ blood pressure under control: At some point, a company’s need to make money is not in line with its supposed desire to do good.
The problem with likes is that they mark out how successful or happy others are, which in turn can promote a feeling of envy and insecurity. It’s a real phenomenon. However, Facebook would certainly want you to post things that get more likes. The company’s success relies upon you posting more and encouraging more “engagement” from other people so that the value of Facebook’s targeted ad business increases.
Facebook’s reliance on engagement is deep-rooted, and it destroys a supposed desire to prevent the platform from encouraging envy. Without doubt, hiding likes can have some benefit, but the way Facebook is built means that this will always be a small step at best.
1. Why does Facebook try hiding likes on its main platform?| A．To catch more users’ eyes. | B．To get involved in an experiment. |
| C．To reduce users’ negative feelings. | D．To encourage users’ posting positive things. |
| A．Facebook shows less concern for users’ mental health. |
| B．Facebook focuses more on the users’ interests. |
| C．Facebook makes a health y profit from the users. |
| D．Facebook outperforms McDonald’s in terms of service. |
| A．More users’ needs. | B．The growth of value. |
| C．The increases of desire. | D．More users’ security. |
| A．Negative. | B．Positive. | C．Indifferent. | D．Objective. |
【推荐2】More than half of Beijing’s adult single children don’t want to have two kids, even though the national policy allows them to do so.
The country’s family planning policy of the late 1970s restricted(限制)urban families from having more than one child to control population growth. However, a new survey shows 52 percent of those now-grown-up single children, who are allowed to have two children, do not want a second child.
Beijing has about 2 million only-child adults. More than 1,100 people from only-child families, aging 20 to 34, were polled(对……进行民意测验). Only 24 percent of them said they would like to have two children. More than a quarter of them would choose a “DINK”(double income, no kids)lifestyle. Survey figures showed that respondents with a basic education wanted 1.1 children on average, those with a bachelor degree wanted 1.3, and those with masters or higher degrees wanted 1.5 children.
“Beijing has had a super low birth rate—less than 1.3 children in a family on average for nearly 20 years, causing increasing pressure on the country’s aging population,” Hou Yafei, a professor with the institute, said. Hou said that the top four factors that determined people’s desires to have children were “income, child care, housing and policy conditions”. “The government should encourage couples from one-child families to have a second child and should provide better welfare services,” Hou said.
The survey also found that people with higher education backgrounds want to have more children because they are more confident about their future.
To promote a higher population growth rate, some provincial governments have relaxed rules and allowed more people to have more than one child. In Shanghai, the death rate has exceeded the birth rate for more than 10 years, and less than 30 percent of only-child couples have had a second child.
1. What is this passage mainly about?| A．Beijing has kept a super low birth rate for 20 years. |
| B．Most Beijing only-child couples just want one child. |
| C．The country’s family planning policy should be stopped. |
| D．The government allows people to have more than one child. |
| A．About 500,000. | B．About 400,000. |
| C．About 300,000. | D．About 200,000. |
| A．Earnings. | B．Ages. |
| C．Parents care. | D．Schooling policy. |
| A．The birth rate in Shanghai will increase soon. |
| B．The government has taken steps to change the situation. |
| C．The country’s family planning policy aims to help live longer. |
| D．People with lower education backgrounds want to have more kids. |
【推荐3】In 1849, travelers going from the East Coast to the West Coast of the U.S. had three choices. They could go by wagon(马车) across the dangerous land. They could travel by sea to Panama, cross Panama by foot, and then sail to the West Coast. The third choice was to board a sailing ship in New York bound for California. The journey took long. Severe weather could add as much as five extra months to the trip.
Could there be any other way to travel from the Atlantic to the Pacific? The answer was a canal. A canal is a human-made waterway.
In the1850s,the U.S. and Britain negotiated treaty(条约) for the rights to build canal. However, this canal was never built.
Panama was another logical option for a canal. With a canal in Panama, travel time could be three months instead of eight months.
In 1879, France began to build a canal across Panama. This project was led by Ferdinand, the experienced builder of the Suez Canal in Egypt. The French government felt that he could get the job done.
Unfortunately, problems began as soon as construction started. It rained every day and temperatures climbed as high as 130 degrees. Tropical diseases caused illness or death to the majority of workers. These factors put a great deal of stress on the project. The money assigned to build the canal quickly ran out. In 1899, France abandoned the project.
The U.S. Congress decided to finish the canal. The U.S . government paid $40 million to France for the completed work and abandoned equipment. In 1903, a treaty between the U.S. and Panama was signed paying Panama $10 million for the land for the canal. This treaty also guaranteed $250,000 to Panama each year for the use of its land and ensured its independence. This deal was viewed as a major foreign policy achievement at the time.
By early1913, the canal was nearly complete. On September 26,1931, an old tugboat was the first ship through the canal. Thousands of people watched and cheered.
Time, money, and possibly even lives have been saved as ships use the shorter route from ocean to ocean provided by the canal. The Panama Canal, a highway of water, is a phenomenon.
1. What does the underlined word “phenomenon” in the last paragraph probably mean?| A．Disaster | B．Wonder. | C．Case. | D．Supply. |
| A．France incorrectly believed in Ferdinand. |
| B．Ferdinand managed another canal project in Egypt. |
| C．Tropical diseases infected most workers on the project |
| D．The U.S. government paid France and took over the project. |
| A．It caused feelings of hate between France and the U.S. |
| B．It strengthened the relationship between Panama and the U.S. |
| C．It united the people living on the east and west coasts of the U.S. |
| D．It created pressure on the relationship between Britain and the U.S. |
| A．To persuade readers to visit the Canal. |
| B．To inform readers about the Canal and its history. |
| C．To tell interesting facts about who built the Canal. |
| D．To state building the Canal was a good political decision. |
