A blind fish living within a Mexican cave system’s deep, enduring darkness still maintains some ability to sense light. As the cave fish no longer seem to rely on an internal daily cycle and some sleep very little, biologist Inca Stein-dal and her colleagues were keen to see if their bodies can still regulate cyclically through time. Most animals on Earth have an internal clock for this the circadian rhythm (昼夜节律) that uses light levels to make our bodies fit in with our planet’s day and night cycles. This rhythm is then used to cycle through different biological processes that can influence our behaviour, such as our hunger cycles.
The Mexican blind cave fish live in a complex of over 30 isolated caves, within which they have each independently adjusted to the dark. Their bodies are extra sensitive to vibrations (震动), allowing them to sense changes in water currents for navigation (导航) in compensation for their limited or complete lack of sight. This adaptation occurred despite the fish from each cave evolving from the same species with fully functioning eyes. This ancestral group still lives in the surface waters in the El Albra region of Mexico and some parts of the Southwestern US.
Steindal and her team took tissue samples from the blind cave fish, from three isolated caves, and their surface relatives and tested the cells in different conditions. They detected the activation of several molecular (分子的) clock mechanisms when the cells were exposed to light, even in the cave fish cells. “Non-visual light detection is maintained at a fundamental cell-based level,” the researchers explain,although the cave fish cells did not respond as strongly as those cells from surface fish. While there were some similarities between the fish from the different caves compared to their surface relatives, there were also differences that confirm their biological clock changes each evolved independently of one another via different molecular mechanisms.
“We have provided proof that despite being blind, cells from the Mexican blind cave fish can detect light and make their clocks fit in with a light/dark cycle,” Steindal and her colleagues conclude. The team hopes these can help us learn more about the circadian rhythm and provide an easier way to study animal adaptations to dark environments.
1. As to the cave fish, what did Steindal and her fellows try to find out?| A．If they have a circadian rhythm. | B．If they rely on an internal daily cycle. |
| C．If they need to sleep. | D．If they are able to sense light. |
| A．The Mexican cave fish’s ancestors had normal vision. |
| B．The Mexican cave fish’s home is in the dark deep sea. |
| C．The Mexican cave fish have adapted to darkness. |
| D．The Mexican cave fish have trouble navigating. |
| A．Cave fish’s unique molecular structures. |
| B．Non-visual light detection in cave fish cells. |
| C．The cave fish’s adjustment t0 molecular clock mechanisms. |
| D．Biological clock changes evolved independently. |
| A．Why Do the Mexican Cave fish Live in the Darken“ |
| B．A Blind Cave fish Can Still Perceive Light. |
| C．How Can the Mexican Cave fish Fit in with the Day Cycles? |
| D．The Biological Clocks of the Life in the Sen Are Constantly Changing. |
相似题推荐
【推荐1】
Pesticides might just be a bee's worst enemy. They harm their brains, slow down their reproduction, and even kill their buzz. Now it seems they damage their social lives and reduce their ability to care for their young.
While previous studies have shown that commonly used neonicotinoid（新烟碱类）pesticides make bees sick and affect how they search for food and navigate, a new study gives more of an idea of how these chemicals affect the internal workings of a colony（种群）. Studying these effects has proved difficult, so the team employed a new technique. They stuck tiny QR codes to the backs of humblebees and tracked their movements using a robotic camera.
The researchers looked at 12 colonies housed in a lab, giving some the same level of imidacloprid—the world's most commonly used pesticide—that they'd be exposed to in the wild while keeping others pesticide-free as controls. They checked on them for a few minutes 12 times a day. The findings are published in the journal Science.
Unfortunately, the researchers found a number of obvious differences between the bees exposed to the pesticide and the controls. The bees given neonicotinoids spent less time interacting with other bees and more time resting. This pause in activity tended to happen more at night, but the researchers aren't sure why.
"Bees actually have a very strong circadian rhythm（生理节奏）," lead author James Crall explained in a statement. "So what we found was that, during the day, there was no statistically observable effect, but at night, we could see that they were crashing. We don't know yet whether the pesticides are destroying circadian gene regulation or if this is just some, maybe physiological feedback…But it suggests that, just from a practical perspective, if we want to understand or study these compounds, looking at effects overnight matters a lot."
1. What does the new study suggest about pesticides' effect on bees?| A．Pesticides lead to their disease. |
| B．Pesticides slow down their brain function |
| C．Pesticides upset their community. |
| D．Pesticides damage bees' internal parts. |
| A．The tools used to observe the bees. |
| B．The data recorded by the robotic camera |
| C．The researchers conducting the experiments. |
| D．The bees kept free from the pesticides. |
| A．The circadian rhythm of bees is stronger during the day. |
| B．It is vital to study the performance of bees at night |
| C．It is certain that pesticides affect bees only at night. |
| D．The pesticides do great harm to circadian gene regulation of bees. |
| A．To inform people of the worrying effects of pesticides. |
| B．To check the best time to observe experimental results. |
| C．To call for the toughest ban on the chemicals. |
| D．To recommend measures to improve the quality of pesticides. |
【推荐2】A couple carved out a life on a small rock island, among the seabirds. The Bass Rock is a small volcanic island just off the east coast of Scotland. Remarkable in the Scottish imagination for its landform and location in the Firth of Forth near Edinburgh, the island has had a thin and intermittent(断断续续)human population across the centuries. Its most notable and sustained inhabitants are the northern gannets that have lived on the island throughout recorded history. With a population of roughly 150,000 birds, their home is the largest in the world.
The English naturalist June Nelson is one of the few people who have lived on the Bass Rock. For three years in the early 1960s. she and her late husband, the ornithologist Bryan Nelson. who was researching gannets at the University of Oxford, made the island their temporary home. Living and working out of a small church, they devoted themselves to observing and recording the behaviors and ecology of the birds. The then-newly-married had little contact with the outside world, but led a happy life together.
In the short documentary Life on the Rocks, Nelson revisits her full and focused years on the Bass Rock. Combining cinematic black-and-white shots of the island with music. the UK director George Pretty creates a vivid account of Nelson’s unforgettable time there, as well as her emotional return. Mining Nelson’s memories and old photographs, the film explores how the husband-and-wife team found happiness on this unique patch of Earth, and among its many birds. But, more than just a fondness for the past, Nelson communicates an urgency to protect the plummeting(暴跌)global sea-bird population, which has declined by 70% in her lifetime, asking “What right have we to deprive(剥夺)future generations of this wonderful place?”
1. What do we know about the Bass Rock from Paragraph 1?| A．It is owned by a couple. | B．It is heavily populated. |
| C．It is gannets’ largest habitat. | D．It is famous for its scenery. |
| A．To research birds. | B．To make their home. |
| C．To live a happy life. | D．To stay away from the outside. |
| A．Nelson’s research about the birds. | B．The couple’s fondness for the past. |
| C．Nelson’s description of the island. | D．Nelson’s concerns about the birds’ situation. |
| A．Tough but worthwhile. | B．Dangerous but admirable. |
| C．Smooth and fruitful. | D．Inspiring and lucky. |
【推荐3】In early February 2019, 51-year-old Rainer Schimpf and his team set out to film South Africa’s Sardine Run off the coast of Point Elizabeth Sardine Run, the annual migration(迁徙)of billions of sardines (a small sea fish), is a big draw for large predators, especially the dolphin and whale. Predators are animals that kill and eat other animals. In an attempt to obtain the best images of the incredible natural phenomenon, Rainer dived into the middle of a spinning ball of fish. Suddenly the sea moved around violently, and the experienced diver and his photographer Heinz Toperczer, who was filming from the boat, instantly realized something strange was going on Suddenly dolphins shot out of the water, a white spray came out and then a whale appeared and grasped Rainer
While Toperczer was filming the terrifying turn of events with his video camera, Rainer, who was trapped had first and engulfed(吞噬)in darkness inside the whales mouth, was trying to survive. Nothing can actually prepare you for the event when you end up inside the pure instinct(本能), "the diver told Barcroft TV. “Knowing in the whale’s mouth, I tried to control my fear. But I was convinced that it was going to dive down and release me much deeper in the ocean.”
The whale quickly realized he was no sardine! As the whale turned sideways, he opened his mouth slightly to release me, and I was washed out, together with what felt like tons of water, of his mouth, " recalled Rainer. Though the entire incident lasted just 1. 8 seconds, it felt like a year to Rainer.
Still holding his underwater camera in his hand. the diver swam to his boat, where he was quickly rescued by the members of the team. The terrible adventure did not disturb Rainer for too long. After checking to ensure he had no injuries, the diver returned to the water to seek out more
1. Which of the following is the best title of the passage?| A．A Diver's Narrow Escape From A Whales Mouth |
| B．The Annual Migration Of Billions Of Sea sardines |
| C．A Frightening And Fantastic Experience Under Sea |
| D．An Adventurous Trip Off Coast Of Point Elizabeth |
| A．seagull | B．Seals | C．Dolphins | D．tortoises. |
| A．He dived aimlessly | B．He cried desperately. |
| C．He panicked immediately. | D．He struggled violently. |
| A．intelligent | B．generous | C．flexible | D．fortunate |
【推荐1】The most detailed study yet of the physics of a finger snap (响指) has shown that in terms of acceleration (加速度), no other body movement comes close. Using high speed cameras, the researchers found that it reached a speed about 20 times faster than the blink of an eye. This “rotational (旋转的) acceleration” was nearly three times greater than the previous record for humans, set by a professional baseball player's arm.
The research, published in the Journal of the Royal Society Interface, divides the finger snap into three stages. First, force is first built up by pressing the thumb and middle fingers together. This appears to be stored in springlike muscle in the fingers and forearm. Friction (摩擦力) between the two fingers acts like a latch (门闩), preventing the energy from being released. Eventually, an “unlatching” process begins, with the thumb moving sideways and the middle finger quickly sliding past the thumb, starting the snap motion. The middle finger then slips into the palm, generating shockwaves that result in a “pop” sound.
The study was inspired by the Hollywood movie Avengers: Infinity War and the character Thanos, who destroys half the universe by snapping his fingers. He does this while wearing a metal glove. When they saw this scene, Dr Saad Bhamla, the leading researcher, and his colleagues asked themselves if this was possible - could you snap your fingers while wearing a metal glove?
They explored the role of friction by covering fingers with different materials, including metallic thimbles (金属套管), which reduced friction. The researchers concluded that a “Goldilocks zone” of friction was necessary. Too little friction and not enough energy was stored to power the snap. Too much friction led to displacement of energy as the fingers took longer to slide past each other, “wasting” the stored energy as heat. “Our results suggest that Thanos could not have snapped because of his metal armoured fingers. So, it's probably the Hollywood special effects, rather than actual physics, at play,” said Bhamla.
1. What can we learn from paragraph 1?| A．The finger snap is the fastest acceleration of our body. |
| B．The blink of an eye is faster than a finger snap. |
| C．People can have faster acceleration if they want. |
| D．Baseball players have the fastest acceleration. |
| A．The position of the thumb. | B．The rotational acceleration. |
| C．Friction between two fingers. | D．Potential energy from pressing fingers. |
| A．They questioned a movie scene. |
| B．They suspected the function of fingers. |
| C．They wanted to prove a theory in the movie. |
| D．They hoped to create different movie scenes. |
| A．A finger snap can happen in any movie. |
| B．Wearing a metal glove can snap a magic sound. |
| C．The finger snap of Thanos in the movie is just a play. |
| D．The friction between fingers is occasionally out of control. |
【推荐2】Some people can walk into a room and instantly put everyone at ease. Others seem to make teeth clench and eyes roll no matter what they do. A small body of psychology research supports the idea that the way a person tends to make others feel is a consistent and measurable part of his personality. Researchers call it “affective presence”.
This concept was first described nearly 10 years ago in a study led by Noah Eisenkraft, a business professor at Washington University. He put business-school students into groups, had them register for all the same classes for a semester, and do every group project together. Then the members of each group rated how much every other member made them feel eight different emotions: stressed, bored, angry, sad, calm, relaxed, happy, and enthusiastic. The researchers found that a significant portion of group members’ emotions could be accounted for by the affective presence of their peers.
It’s been known for some time that emotions are infectious. But affective presence is an effect one has regardless of one’s own feelings—those with positive affective presence make other people feel good, even if they personally are anxious or sad, and the opposite is true for those with negative affective presence.
Unsurprisingly, people who consistently make others feel good are more central to their social networks—in Elfenbein, s study, more of their classmates considered them to be friends. Hector Madrid, an organizational-behavior professor, has found that leaders with positive affective presence have teams that are better at sharing information, which leads to creativity. Inferiors are more likely to voice their ideas, too.
However, Elfenbein notes that positive affective presence isn’t naturally good. Neither is negative affective presence necessarily always a bad thing in a leader—think of a football coach yelling at the team at halftime, motivating them to make a comeback. She suspects that affective presence is closely related to emotional intelligence which one can use to cure cancer or to be a criminal mastermind.
1. What does the underlined phrase “make teeth clench” in Paragraph 1 mean?| A．Make people nervous. | B．Make people glad. |
| C．Make people comfortable. | D．Make people calm. |
| A．To suggest leaders are better at sharing information. |
| B．To prove leaders also have negative affective presence. |
| C．To indicate people with positive affective presence are creative. |
| D．To show positive affective presence can promote social interaction. |
| A．It is for motivating others. |
| B．It is a double-edged sword. |
| C．It is affected by one’s own emotion. |
| D．It is the positive emotional influence on others. |
| A．Affective Presence: Secret Part of Your Personalities |
| B．Emotional Signature: Why Emotions are Infectious |
| C．Affective Presence: How You Make People Feel |
| D．Emotional Intelligence: Big Part of Affective Presence |
【推荐3】Medical News Today reports a rise in the number of dogs trained to find out cancer, diabetic conditions, bacterial infections and other health problems.
Research from the UK charity Medical Detection Dogs and the US organization Dogs4Diabetes has found dogs are being used to warn their diabetic owners when their blood sugar levels are too low. Other research has found dogs are able to find clostridium difficile (艰难梭菌)—a dirty bacterial infection that causes many illnesses acquired in hospitals—in patient stool samples and hospital air.
New research is also examining at the use of dogs to detect various types of cancer—named “ bio-detection dogs”. Earlier this year, Medical News Today detailed how researchers have found dogs are able to detect volatile organic compounds (VOCs), or odorants (有气味的东西), which are altered in the early stages of ovarian (卵巢的) cancer. Another study conducted by researchers at Medical Detection Dogs also found that these VOCs are biomarkers for bladder (膀胱) cancer.
Using four trained sniffer dogs to analyze urine (尿) samples from patients who had bladder cancer, alongside healthy people, the researchers found that the dogs were able to detect the cancer with an accuracy level that ranged from 56 percent to 92 percent.
A dog has up to 300 million scent glands (嗅腺) (a human has about 5 million), which makes a dog’s sense of smell up to 100, 000 times more sensitive than people’s.
“We believe all diseases have smell associated with the diseases, due to the changes occurring within the body, with different organs expressing different chemical compounds, ” Ralph Hendrix, executive director of Dogs4Diabetics, told Medical News Today, “These smells are evident in breath and sweat.”
1. What does the passage mainly talk about?| A．Trained dogs are very clever. |
| B．Trained dogs can find out diseases like cancer, diabetes and so on. |
| C．Dogs that are trained have a good sense of smell. |
| D．Dogs that are trained can follow the rules. |
| A．The dirty air that was polluted in hospitals. |
| B．A special kind of dog that can find out diseases. |
| C．A disease that cannot be cured. |
| D．A dirty bacterial infection that results in many illnesses in hospitals. |
| A．He thinks dogs, smell influences patients’ moods. |
| B．He thinks dogs, smell influences patients, behavior. |
| C．He believes the diseases have something to do with smell. |
| D．He believes the diseases have something to do with lifestyle. |
【推荐1】The fire of creativity doesn’t necessarily burn out after youth.“Many people believe that the creativity is exclusively (专有地) associated with youth, but it really depends on what kind of creativity you’re talking about,” says the lead study author, Bruce Weinberg of Ohio State University.
According to the study, there are two types of innovators (创新者): conceptual and experimental. Weinberg and fellow researcher David Galenson think that those who tend to do their best work in their mid-20s are conceptual innovators, while those who peak in their 50s are experimental innovators.
Weinberg and Galenson studied the works of 31 Nobel Prize winners of economics, placing the economists on a range of most conceptual to most experimental. The age at which an economist contributed the most well-regarded to the field was taken into account, and the age at which the work entered the economic field helped to classify the economist’s creative peak (顶峰).
Economists with a conceptual approach peaked in their 20s, while those who took the experimental approach peaked in their late 50s. Most of the winners made their great discoveries after at least 25 years of hard work.
The researchers correlated (与……相关联) their findings in economic achievements with those of scientific achievements. For example, they mention Albert Einstein as a conceptual innovator, who put forward the famous Special Theory of Relativity at the age of 26. They suggest scientist Charles Darwin developed his most groundbreaking theories later on in life, which would make him an experimental innovator. This makes sense given that the theory of evolution was developed over many years through a long process of trial and error.
None of this is to say that either type of innovative approach is exclusive to different age groups. It isn’t unheard of for an older person to be a conceptual innovator or for younger people to innovate more experimentally. The research simply shows trends. Anyhow, there's always a little room for a creative breakthrough — no matter your age
1. Which of the following is the best title of the passage?| A．Creativity Is The Best When One Is Young |
| B．Scientists Became Famous At Different Ages |
| C．Experimental Innovators Peak In Late 50’s |
| D．Creativity Isn’t Exclusive To The Young |
| A．most winners made creative discoveries in their late 20’s |
| B．award-winning economists tend to use conceptual approaches |
| C．the majority of 31 winners were experimental innovators |
| D．researchers interviewed Nobel Prize winners of economics |
| A．They inspire their creative ideas by a sudden spark. |
| B．They slowly cultivate creative ideas over a long time. |
| C．They tend to challenge most basic scientific concepts. |
| D．They often make important contributions in literature. |
| A．The findings are also applied to scientific field. |
| B．Scientists make breakthroughs by trial and error. |
| C．Economic theories are based on scientific facts. |
| D．Scientific discoveries call for many years of work. |
【推荐2】Portraits as Art
According to a dictionary, portraiture is “a representation (描绘) of a person, especially of the face by drawing or painting a likeness.” However, this definition neglects the complexities of portraiture. Portraits are works of art that engage with ideas of identity rather than just a likeness. These concepts of identity involve social rank, gender, age, profession, character of the subject, etc. It is impossible to copy all the aspects of identity. Therefore, portraits reflect only certain qualities of subjects. Portrait art has also undergone significant shifts in artistic practice. The majority of portraits are the outcome of current artistic fashions and favored styles. Therefore, portrait art is an art category providing various engagement with social, psychological, and artistic practices and expectations.
Since portraits are different from other art categories, they are worthy of separate study. During their production, portraits require the presence of a specific person, or an image of the individual. In many instances, the production of portraiture has required sittings, which result in interaction between the subject(s) and the artist throughout the creation of the work. In certain instances, portrait artists depended on a combination of different involvement with their subjects. If the sitter can’t sit in the studio regularly, portraitists could use his or her photographs. In Europe, during the seventeenth and eighteenth century, the sitting time was sometimes decreased by focusing only on the head. Theoretically, portraitists could work from impressions or memories when creating a painting, but this rarely occurred according to documented records. Nonetheless, whether the work is based on model sittings, copying a photograph, or using memory, the process of painting a portrait is linked with the model’s attendance.
Furthermore, portrait painting can be distinguished from other artistic categories by its connection with appearance, or likeness. As such, the art of portrait painting got a reputation for imitation instead of for artistic innovation. Based on Renaissance art theory, portraiture was related to the level of a mechanical exercise as opposed to a fine art. Michelangelo’s well-known protest against portraits is only one example. During the nineteenth and twentieth centuries, the attitude to portraiture was critical. Even so, artists from around the globe persisted in painting portraits despite their theoretical objections. Picasso, for example, became widely-known for cubist still-life painting (立体派静物画) early in his career, but some of his early experiments in this new style were his portraits of art dealers.
1. What does paragraph 1 mainly tell us?| A．The changing definition of portraiture reflects shifting attitudes to it. |
| B．Most portraits reflect artistic fashions and favored styles when created. |
| C．Portraiture is a more complex art form than is defined in a dictionary. |
| D．Portrait art shouldn’t be seen as a distinct art category for its complexity. |
| A．Portraiture typically takes much less time than other art forms. |
| B．Portraiture often requires frequent cooperation between artists. |
| C．Portraits show models in a more accurate way than other art forms. |
| D．Portraits generally involve interaction between subjects and artists. |
| A．based their work on the subjects’ attendance |
| B．preferred models’ photographs to their presence |
| C．were more willing to use impressions or memories |
| D．reduced sitting time to concentrate on a sitter’s head |
| A．altered the way other artists felt about portrait art |
| B．created portraits in spite of his objection to portrait art |
| C．depended on portrait art to establish a higher reputation |
| D．had fewer theoretical objections to portraitures than others |
【推荐3】It’s interesting that technology often works as a servant for us, yet frequently we become a servant to it. E-mail is a useful tool but many feel controlled by this new tool. The average business person is getting about 80e-mails per day and many feel that about 80% of the messages in their “Inbox” are of little or no value. So, I have four suggestions to help you to become better at “Erasing E-mail”.
1.Get off the lists. The best way to deal with a problem is to never have it. If you are receiving a lot of unwanted e-mails, ask to be removed from the various lists. This would include your inclusion in unwanted lists.
2.“Unlisted address”. Just as you keep an “unlisted” telephone number that you share only with those whom you want to have direct access to, you might want to get a separate e-mail address only for the important communications you wish to receive.
3.Check it once or twice per day. Many I speak with are becoming chained to their email server, monitoring incoming email continuously. Maybe this is because e-mail creates its own sense of urgency, but most of thecommunications are not all that urgent. I respond to them a couple of times per day.
4.Deal with it. As you open each e-mail, do one of the following:
a. If it requires a quick response, respond to it and delete it.
b. If it requires a response but is not the best use of your time, try to find someone else to do it.
c. If it is going to take any serious amount of time to respond, schedule it for action in your Day Planner andthen download the message, save it, or print it out for future action.
I personally receive about 250 e-mails per day and by practicing the suggestions above, I can handle thatvolume in about an hour, taking advantage of this fantastic tool but not being controlled by it to make sure I’mdoing more important tasks in my day.
1. For the important communications, the writer suggests that you ________.| A．have a direct access for them |
| B．have several e-mail servers for them |
| C．get a separate e-mail address for them |
| D．get an unlisted phone number for them |
| A．respond urgent ones only |
| B．reply to all of them at the same time |
| C．handle them a couple of times daily |
| D．keep replying to e-mails all day long |
| A．responding right away if it’s urgent |
| B．downloading every e-mail before you reply |
| C．scheduling it for later reply if it takes much time |
| D．asking someone else to reply to it if it’s not at your convenience |
