Dogs tend to ignore suggestions from people who are lying. This is what Ludwig Huber’s team at the University of Vienna in Austria found in its recent experiment.
In the experiment, Huber and his colleagues first trained 260 dogs of various pure breeds to find hidden food in one of two covered bowls. The dogs learned to follow the suggestion of a person they had never met—the “communicator”—who would touch the food-filled bowl, glance at the dog, and say, “Look, this is very good!” Dogs appeared to trust this new person when they were reliably following the signal, says Huber.
Once that trust was established, the team had the dogs witness another person move the food from the first to the second bowl. The communicators were either in the room, and also witnessed the switch, or were briefly absent and so apparently unaware that the food had been switched. In either case, the communicators would later recommend the first bowl—which was now empty.
In previous versions of this experiment with children under age 5, Japanese macaques or chimpanzees, the participants reacted in particular ways. If a communicator had been absent during the food switch, it would appear that they couldn’t know where the treat really was. As such, the children, chimps or macaques would typically ignore a communicator who gave honest—but misleading—advice on where the food was, says Huber.
However, if the communicator had been in the room and witnessed the switch, but still recommended the first (now empty) bowl, young children and non-human primates (灵长目动物) were actually much more likely to follow the communicator’s knowingly misleading suggestion to approach the empty container. This may be because the children and non-human primates trusted the communicator over the evidence of their own eyes, says Huber.
The dogs in the new experiment, however, weren’t so trusting of lying communicators—much to the researchers’ surprise. Half of the dogs would follow the communicator’s misleading advice if the communicator hadn’t witnessed the food switch. But about two-thirds of dogs ignored a communicator who had witnessed the food switch and still recommended the now-empty bowl. These dogs simply went to the bowl filled with food instead. “They did not rely on the communicator anymore,” says Huber.
“This study reminds us that dogs are watching us closely, are picking up on our social signals, and are learning from us constantly even outside of formal training contexts,” says Monique Udell at Oregon State University.
Besides, the fact that half the dogs trusted the communicator who seemed to have made an honest mistake could reveal a lot about how dogs process social information, says Udell. “There is both genetic and behavioral evidence that dogs are hypersocial, meaning that many dogs have a difficult time ignoring social cues even when another solution might be more advantageous,” she says. “This is a really striking example of just how often this may occur.”
1. What did Huber and his colleagues try to do first?| A．To let dogs trust a stranger. | B．To train dogs to guide humans. |
| C．To communicate more with dogs. | D．To improve dogs’ ability to seek food. |
| A．They would be misled by the communicator. |
| B．They would ignore the communicator’s advice. |
| C．They would teach the communicator a good lesson. |
| D．They would keep a distance from the communicator. |
| A．Dogs tend to follow the communicator’s advice. |
| B．Dogs can be easily confused by the food switch. |
| C．Dogs can identify whether the communicator is lying. |
| D．Dogs can accurately understand humans’ social signals. |
| A．They are much smarter than humans. |
| B．They prefer to stay with honest humans. |
| C．They need to be trained to follow humans. |
| D．They can be easily influenced by social cues. |
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【推荐1】A butterfly’s wings can have many jobs besides keeping the insect high up in the air. They may be used to attract mates, or to warn potential attackers to stay away. All of these roles, though, depend on their unchanging colouration. This plays into the idea that butterfly wings are dead tissue, like a bird’s feathers. In fact, that’s not true. For example, in some species males’ wings have special cells releasing some chemicals which attract females.
Nanfang Yu, a physicist at Columbia University, in New York, has been looking into the matter. Together with Naomi Pierce, a butterfly specialist at Harvard University, he has now shown, in a paper published in Nature Communications in February, 2020, that butterfly wings are, indeed, very much alive.
In their experiments, the two researchers used a laser(激光) to heat up spots on the wings of dozens of butterfly species. When the temperature of the area under the laser reached 40°C or so, the insects responded within seconds by doing things that stopped their wings heating up further. These actions included a butterfly turning around to minimize its profile to the laser, moving its wings up and down or simply walking away.
Butterflies engaged in all of these heat-minimising activities even when the researchers blindfolded them. That suggested the relevant sensors were on the wings themselves. Dr Yu and Dr Pierce therefore searched those wings for likely looking sensory cells. They found some, in the form of neurons(神经元) that were similar to heat detectors known from other insects. They also uncovered disc-shaped cells that appeared to be similar to pressure-sensitive neurons. They guess that these are there to detect deformation of the wing—information an insect could use to control its flight pattern.
The third discovery they made to contradict the “dead wing” idea was that some butterfly wings have a heartbeat. A butterfly’s wings have veins(静脉). These carry a bloodlike liquid which, researchers have now found in males, shows a pulse(脉搏) of several dozen beats per minute. The source of this pulse appears to be the scent(气味) pad, a dark spot on the wings that produces the female-attracting chemicals. Apparently, this “wing heart” acts as a pump that helps bloodlike liquid through the scent pad.
In all their experiments simulating different environmental conditions, Dr Yu and Dr Pierce consistently found that, different parts of the wing are covered by different sorts of scales(鳞屑). In particular, tubes pass through scales over the scent pads. This improves their ability to spread heat away and helps keep the living parts of a butterfly’s wings alive.
1. A bird’s feathers are mentioned in Paragraph 1 to _____.| A．introduce the latest research findings on a bird |
| B．highlight the special feature of a bird’s feathers |
| C．show common knowledge about butterfly wings |
| D．stress the difference between a butterfly and a bird |
| A．Butterfly wings are complicated living organs. |
| B．Butterfly wings have little reaction to external heat. |
| C．The scent pads on some male butterfly wings are their hearts. |
| D．Heat-minimising activities help detect deformation of the wings. |
| A．Attracting mates. | B．Increasing blood flow. |
| C．Covering powerful tubes. | D．Producing the cooling effect. |
| A．Seeing Is Believing | B．More Than Meets The Eye |
| C．Nothing Seek, Nothing Find | D．Fine Feathers Make Fine Birds |
【推荐2】As we all know, trees are important to our life. They provide us with food, wood and most importantly, oxygen. Now there is one more thing we can add to this list—blocking out harmful bacteria in water.
The discovery was made by some scientists and high school students who were seeking for a natural water filter(过滤器)—one that could help people in developing countries that don’t have access to modern water systems.
The researchers, led by Rohit Karnik, a professor ,decided to turn to trees for help because they were able to allow liquid to flow through while blocking out air bubbles(气泡）.
They began by cutting 1.5-inch-wide sections of tree bark from the branch of a white pine tree. The researchers then tested the wood’s filtering ability by pouring water containing red dye particles(染料颗粒)of different sizes through. To their surprise, they found it was effective in trapping all the particles. Encouraged, the team did another experiment, this time with water containing bacteria. Sure enough, the bark held back 99%of the bacteria, allowing only 1% to flow through.
Mr. Karnik said the bark was able to filter water containing much smaller particles. This means that it can be used to get rid of most of the bacteria. However, what troubles them is that tree bark cannot hold back viruses, which tend to be much smaller.
Though the experiment is successful, we must remember one thing—the bark only works when damp. This means that before this natural filter can be put to practical use, the researchers will have to figure out how to keep the bark damp, or find a way to keep the bark’s great filtering ability even when it’s dry.
But the study is not done. The researchers plan on testing other types of trees, including those flowering trees. They think those may be more effective in trapping smaller particles and even viruses.
1. How will the discovery affect the world?| A．No harmful bacteria will be found in water. |
| B．There will be no water pollution around the world. |
| C．More pine trees will be planted around the world. |
| D．Clean water will be more accessible in developing countries. |
| A．Viruses cannot be prevented. |
| B．Tree bark should be wet. |
| C．It’s hard to remove air bubbles. |
| D．Not all bacteria can be held back. |
| A．To find other natural water filters. |
| B．To improve the filtering ability of other trees. |
| C．To find a way to keep the bark wet. |
| D．To test the filtering ability of other trees. |
| A．Culture. | B．Science. |
| C．Lifestyle. | D．Society. |
【推荐3】An elephant and a crocodile were once standing beside river. They were disputing which was the better animal.
“Look at my strength,” said the elephant. “I can pull up a tree, roots and all with my trunk”
“Ah! But your skin is not nearly so thick as mine,” replied the crocodile. “No knife or tooth can cut through it.”
Just as they were coming to blows, a lion happened to pass.
“My dear friends!” said the King of all animals, going up to them. “Let me know the cause of your disagreement.”
“Will you kindly tell us which is the better animal?” cried both at once.
“Certainly”, said the lion, pointing across the river. “Do you see the soldiers’ metal hat on that wall?”
“Yes!” replied the beasts.
“Well, then,” continued the lion, “go and get it, and bring it to me, and I shall be able then to decide between you.”
Upon hearing this, off they started. The crocodile, being used to the water, reached the opposite side of the river first, and was soon standing beside the wall.
Here he waited till the elephant came up. The elephant, seeing that the crocodile had no way of reaching their goal, raised his long trunk, and took down the hat quite easily.
They then made their way together back again across the river. The elephant was trying to keep up with the fast-moving crocodile in the water and became careless. When he was forced to turn sharply to avoid a floating tree branch, the elephant dropped the hat and it fell to the river bottom. The crocodile noticed the accident, so down he dived, and brought it up in his huge mouth. They then returned, and the crocodile laid the metal hat at the lion's feet. The King took it up, and turning to the elephant, said: “You, because of your size and trunk, were able to reach the hat on the wall but, having lost it, you were unable to get it back. And you,” said the lion to the crocodile, “although unable to reach the hat, were able to dive for it and save it. You are both wise and able in your own ways. One is no better than the other.”
1. The underlined word "disputing" in Paragraph 1 means____.| A．playing | B．quarrelling | C．complaining | D．deciding |
| A．His big mouth | B．His strong skin | C．His swimming skill | D．His dangerous teeth |
| A．He ordered them to fight. | B．He made a quick decision. |
| C．He suggested a competition | D．He asked them to describe themselves |
| A．The hat got wet in the river. | B．He hit a floating tree |
| C．He was trying to swim too fast | D．He wanted to fight the crocodile |
| A．By working together | B．planning carefully |
| C．By sharing their ideas | D．By listening to the lion |
【推荐1】There is a huge need for shark fins（鳍）in Asian countries. As a result, many sharks are caught and killed. According to reports, sharks are being killed at an shocking rate of up to 273 million worldwide every year.
Some experts predict that if the killing continues at the present rate, many shark species will be lost forever. It can be very dangerous. Sharks are very important and they should be protected.
In a study of the east coast of the United States, 11 species of sharks died out. Of the 14 species of ocean life that those sharks used to eat, the populations of 12 exploded and caused great damage to the ecosystem（生态系统）. For example, the cownose ray（鳐）population was no longer kept under control by sharks and so grew out of control. As a result, the rays destroyed the population of bay scallops（扇贝）, their favorite food. The scallop fishery, which had been in good condition for over 100 years, was destroyed completely. Also, the removal of the scallops most likely had an effect on water quality as they were no longer there to clean the water.
Sharks tend to eat very efficiently（高效地）, going after the old, sick, or slower fish in a population, keeping that population healthy. Sharks help keep many populations of ocean life to the right size so that those prey（猎物）species don't do harm to the ecosystem by becoming too populated. The ocean ecosystem is made up of very complex（复杂地）food webs. For the most part, sharks are at the top of these webs and are considered by scientists to be "keystone" species, meaning that removing them may cause the whole structure to fall apart. Therefore, we should protect sharks because doing so is to protect the whole ecosystem.
1. Why are so many Sharks killed in Asia?| A．They are dangerous. |
| B．They are threats to other species. |
| C．They caused great damage to the ecosystem. |
| D．The body parts that are considered valuable are in great need. |
| A．Loss of money. | B．Improvement of water quality. |
| C．Damage to local ecology. | D．An increase in the variety of animals. |
| A．Nature. | B．Life. | C．Sports. | D．Economy. |
| A．Illegal hunting of sharks. |
| B．The living habits of sharks. |
| C．Wildlife protection in the United States. |
| D．The reasons why should humans protect sharks. |
【推荐2】A dog snoring away the afternoon on the living room floor. Walruses napping belly-up on a beach. Lions stretching out on the grassland. These sleepy scenes may make people wonder why these other mammals（哺乳动物）seem to be getting so much more sleep than humans. Do they actually need more sleep? Are they just sleeping because they can?
Though constantly studied, sleep is one of the great mysteries modern science hasn’t completely cracked. “We really don’t know what sleep is for,” said Dr. David Raizen.
However, the matter is far from settled.
As for human sleep? Raizen said the most important thing is for people to listen to their bodies and get as much sleep as they feel they need.
| A．Nobody knows. |
| B．Should humans be sleeping more, too? |
| C．More efforts are being put in interpreting sleep better. |
| D．Scientists are doing research trying to find the answer. |
| E．Sleep is complex, hard to measure in wild animals and even harder to interpret. |
| F．One idea is that sleep in mammals has something to do with body size and diet. |
| G．It is about eight hours for most folks but might be as few as five and as many as eleven. |
【推荐3】Men with shaved heads are perceived to be more masculine, dominant and, in some cases, to have greater leadership potential than those with longer locks or with thinning hair, according to a recent study out of the University of Pennsylvania’s Wharton School.
Some executives say the style makes them appear younger — or at least, makes their age less evident — and gives them more confidence than a comb-over or monk-like pate.
Wharton management lecturer Albert Mannes conducted three experiments to test peoples’ perceptions of men with shaved heads. In one of the experiments, he showed 344 subjects photos of the same men in two versions: one showing the man with hair and the other showing him with his hair digitally removed, so his head appears shaved.
The study found that men with thinning hair were viewed as the least attractive and powerful of the bunch, a finding that tracks with other studies showing that people perceive men with typical male-pattern baldness as older and less attractive. For those men, the solution could be as cheap and simple as a shave.
New York image consultant Julie Rath advises her clients to get closely cropped when they start thinning up top. “There’s something really strong, powerful and confident about laying it all bare,” she says, describing the thinning or combed-over look as “kind of schlumpy.”
1. Which kind of people are more likely to be regarded as leaders?| A．People with long hair. | B．People with thinning hair. |
| C．People with shaved heads. | D．People with young appearance. |
| A．To see people’s opinions on men with shaved heads. |
| B．To distinguish 344 different photos. |
| C．To show how people’s hair is digitally removed. |
| D．To persuade people to keep their hair. |
| A．To have a comb-over hairstyle. | B．To have a shave. |
| C．To make their hair thin. | D．To have a simple haircut. |
| A．Technology | B．Business | C．Environment | D．Lifestyle |
【推荐1】“Hey, little boy, will you support me when I’m getting old?” Wang Wenshan, 35, asked his newborn baby as he hugged him at home.
The Chinese tradition of raising sons to support parents in their old age has been weakened by the rapidly growing economy and improved standard of living. As is the case with more and more developed countries, China faces an aging society. People are living longer and having fewer children. Therefore, many Chinese families are falling into a 4-2-1 family pattern: a couple raises one child and supports four elderly parents. But few realize that a problem is likely to happen ahead.
The aging of the population is a trend that now affects a growing number of countries. The Information Office of the State Council, China’s cabinet, issued（发行） a white paper on measures China has been taking to help its elderly population. The paper said China’s population entered the aging period at the end of the 20th century and the proportion of people aged 60 and above accounted for over 10 percent of the entire population. By the end of 2005, China had nearly 144 million people over 60, accounting for 11 percent of the population, according to the white paper.
An expanding aged population inevitably means that many issues must be settled, as the problem concerns every aspect of society. It puts more pressure on each family, causing disturbing economic consequences and serious social problems. It also challenges the labor force supply and the pension system.
“I used to think that it’s not an issue for me to provide for the aged,” said Wang, whose parents and parents-in-law all enjoy pensions and medical insurance. But last year Wang’s father suffered from a serious illness and afterward Wang began to feel the pressure on his shoulders.
After his father recovered, Wang opened a bank account for each parent and put away some money in the account every month to prepare for future uncertainties. In addition, he has to save money every month to provide for his son’s future education. “I’m now breaking my back to support my family: saving pensions for the parents, my son’s education funds, and living costs.”
Wang also bought some commercial old-age insurance for himself. “We have to take precautions(预防)before it is too late, and many of my colleagues share the same view,” he said.
1. Which of the following is not caused by an aging society?| A．Social problems. | B．Unemployment. |
| C．More pressure on each family. | D．The problem of the pension system. |
| A．the aging problem is one of the concerns of the Chinese government |
| B．China will encourage young couples to have more than one child |
| C．many people have realized the aging problem |
| D．children will not support their parents in China |
| A．Surprisingly. | B．Certainly. |
| C．Hopefully. | D．Evidently. |
| A．China is the only country to face an aging society |
| B．most of the developing countries face an aging society |
| C．countries with a large population face an aging society |
| D．more and more developed countries face an aging society |
【推荐2】Singapore uses about 430 million gallons of water every day—a number it expects could double in the next four decades. That kind of consumption is piling pressure on the Asian city state to address growing concerns about global water shortage. But it has no natural water sources of its own, instead relying heavily on recycled water and imports from its neighbors. It imports approximately 40% of its water today. And with climate change, that water has become far less dependable. So it’s building new technology to prepare itself for a future where obtaining clean water will be even more difficult.
“What we have become used to as reliable water, may quickly change—so we have to be prepared, we have to be thinking about the basic need in advance,” Snyder said. “There’s a big drive to become water independent, which is largely dependent on the technologies we’re developing.”
WateRoam, is already taking innovation from Singapore to the rest of the region. Founded in 2014, WateRoam says it has developed a lightweight, portable filtration (过滤) device that they say has already provided clean drinking water to more than 75,000 people across Southeast Asia.
“We’re going with a plain approach because we’re looking at water as a basic problem and a basic need and as a result, we needs basic technology to solve this problem,” Pong said. “We want people who are ordinary—not specialists or engineers—to be able to pick up this product and know how to use it.”
The water filtration device is no bigger than a bicycle pump, yet it can provide clean water to villages of 100 people for up to two years, according to the company.
1. How will Singapore deal with the water shortage?| A．Detect more natural water resources. | B．Import more water from its neighbors. |
| C．Make full use of the climate change. | D．Develop new technology to reuse the water. |
| A．An invented device. | B．A newly-founded organization. |
| C．A water-related company. | D．A reliable product of Singapore. |
| A．Water is absolutely one of the solved problems. | B．The new product should be easy-to-handle. |
| C．Specialists or engineers are badly in need. | D．Ordinary people can also help in dealing with water. |
| A．Effective but money-wasting. | B．Energy-saving and simple to produce. |
| C．Time-consuming but dependable. | D．Rewarding and easy to carry. |
【推荐3】Adding just a few plants to a bare front garden can lower stress levels and help people feel happier, research suggests.
Researchers introduced decorative plants such as juniper, azaleas, clematis, lavender, daffodil bulbs and petunias into small bare front yards in economically backward streets in Salford, Greater Manchester.
The study by the Royal Horticultural Society (RHS) and the universities of Sheffield, Westminster and Virginia in the US then measured the stress levels of residents taking part in the experiment and asked them how they felt.
Each residents could receive one tree, one climber and enough smaller plants and bedding plants to fill two containers. They were not required to look after the plants, as the containers were “self-watering” with a 22-litre in-built reservoir (蓄水池) of water, but they were encouraged to take part in gardening their plots (小块地), with help from the RHS advisory team.
The team measured residents’ cortisol (皮质醇) — the key stress response hormone (激素) — before and after the plants were added, and found a higher proportion(比例) of healthy daytime cortisol patterns after planting, suggesting they had a better health state.
The research found only 24 per cent of residents had healthy cortisol patterns before the plants went in, but over the year following the greening of the front gardens, this increased to 53 per cent.
More in-depth interviews showed the garden motivated people to do more gardening and repair and paint other areas of their homes and gardens. They also found gardening is relaxing and that it gave them a sense of pride in their homes, and all of them reported the plants made them feel more cheerful and lifted their spirits when they looked at them.
“The stress reduction data is amazing, in that we found such a significant response with just a relatively small number of plants. We can now further evidence the vital need to include plants in our front gardens and domestic spaces,” said Dr Lauriane Suyin Chalmin-Pui, who conducted the research as part of her PhD.
1. What’s the text mainly about?| A．A way to design bare front gardens. |
| B．A tip for lowering the level of cortisol. |
| C．The economic value of decorative plants. |
| D．The positive effect of plants on humans’ health. |
| A．By testing the growing of bedding plants. |
| B．By discovering subjects’ ways of gardening plots. |
| C．By measuring the area of subjects’ front gardens. |
| D．By observing the amount of a chemical substance. |
| A．Researchers should provide further evidence. |
| B．Only front gardens are ideal places for gardening. |
| C．People should garden outside or inside their homes. |
| D．A small number of plants have little influence on stress reduction. |
| A．A diary. | B．A guidebook. |
| C．A magazine of science. | D．A novel. |
