If there is one place you don’t want to stick your finger, it’s the mouth of a Pacific lingcod. These fearsome fish have around 500 needlelike teeth sticking out of jaws (颌) that are strong enough to crush crustaceans (甲壳动物).
How lingcod maintain the sharpness of their terrifying teeth has long been a puzzle. But a study, published in November in the Proceedings of the Royal Society B, claims that Pacific lingcod keep their teeth sharp and shiny by replacing about three percent of them every day. For a lingcod, that’s up to 20 teeth replaced daily.
In order to determine the frequency at which lingcod replace their teeth, Ms. Cohen, a coauthor of the new study, and her colleagues kept 20 lingcod at the University of Washington’s Friday Harbor Laboratories and tracked how many teeth they lost and regrew over several days. The fish were placed in a tank of seawater mixed with a red dye (染料) that colored their teeth, then returned to their regular tank for 10 days. When the 10 days were up, the fish were placed in a tank containing a green dye and then examined. The teeth that were present since the start of the experiment were both red and green, whereas the new teeth were only green.
After collecting and examining a total of 10,000 teeth, the scientists were able to determine how quickly lingcod lost and regrew their teeth and which teeth were replaced most often.
Lingcod, like most fish, have two sets of jaws: oral jaws and pharyngeal jaws. Their oral jaws are used to catch food while their pharyngeal jaws, which are positioned in their throats, are used to chew their food and move it from their mouths to the stomach. Ms. Carr, the lead author, and colleagues found that teeth are replaced more frequently in the back of the mouth, where most of the chewing and crushing take place.
The way lingcod replace their teeth is likely crucial to their hunting strategy, says Kory Evans, a fish ecologist at Rice University in Houston. “The duller a lingcod’s teeth are, the harder it is going to be for it to hold on to its target. So having the ability to shed teeth and replace them is pretty important.” Dr. Evans said, “In order to make it as a lingcod, you need sharp pointy teeth and all your teeth need to be on point.”
1. What does Paragraph 3 mainly talk about?A.What role seawater played. | B.What conclusion was reached. |
C.How the study was conducted. | D.How teeth changed their colors. |
A.every 10 days | B.to better hunt for food |
C.faster in the oral jaw | D.with bigger and sharper ones |
A.Repair. | B.Sharpen. | C.Lose. | D.Examine. |
A.To warn people of the danger of a fish. |
B.To introduce the findings of a new study. |
C.To stress the importance of replacing teeth. |
D.To suggest new ways to conduct studies on fish. |
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【推荐1】Women cry 4,680 times over their adult lifetime — more than twice as much as men, a study has found. Sad TV shows or books, tiredness and arguments their partner mean the average woman will cry six times a month. In comparison, men will shed a tear just three times a month.
But the study found men are less embarrassed (难为情) about crying in front of others, with four in 10 saying they wouldn’t be bothered about shedding a tear in public compared to just a third of women. Psychologist Emma Kenny said, “While women are usually associated with crying, the results of this study actually show that men are now feeling that it’s acceptable to show their emotions through crying. And, different from what is usually believed, the results actually suggest that women feel embarrassed when they let their emotions show.”
The study of 2,000 adults found 51% of women admit to being a big crier — crying often or at little things. But far from shying away from it, three in 10 men are also happy to admit they often shed a tear.
A sad TV show, movie or book is most likely to leave women watery-eyed, while men tear up at sad moments or memories. Other reasons for crying include funerals, grief and anxiety. But women are more likely to cry happy tears, with 40%admitting to shedding a tear for a good reason, something just 24%of men do. And while 64% of women admit to crying for no reason, just three in 10 men can say the same.
The study also found an emotional 44% of men have cried in public, along with a huge 80% of women. Crying in front of people you work with would leave many feeling most embarrassed, followed by their boss, strangers and acquaintances. But almost one in 10 admit they would be left red-faced if they shed a tear in front of their family members.
1. What is a common belief about women according to Paragraph 2?A.They cry when in depression. |
B.They seldom cry for no reason. |
C.They express emotions through crying. |
D.They won’t feel embarrassed when crying |
A.husbands | B.friends | C.workmates | D.strangers |
A.By making a comparison. | B.By giving typical examples. |
C.By using the experts’ words. | D.By offering facts and opinions. |
A.Men Also Cry In Front Of Others |
B.Women Cry Much More Than Men |
C.Women Are More Likely To Cry in Public |
D.Women And Men Cry in Difficult Situations |
【推荐2】Scientists say extreme rainfall happens more often this summer. Nick Goltz is head of the UConn Plant Diagnostic Laboratory at the University of Connecticut in Storrs, Connecticut. He said too much water can mean dead plants in a garden though water is a must for plant life.
Goltz explained that flooding cuts off the oxygen supply which leads to root-rot (根腐) diseases. And then plants cannot pull enough water to survive. The result is yellow, weakening leaves, which would usually show a plant’s need for water. But after flooding, those same signs mean that roots under water cannot function in really wet conditions.
Avoid walking on wet soil if your garden has been affected by flooding. Wait until the soil has mostly dried before looking at the damage. Adding any weight or pressure to wet soil can cause even more oxygen to be pressed out from around struggling roots. Plants weakened or stressed by flood water can more easily get diseases and unwanted insects. So keep an eye on them and treat problems as they come, which could be months later. Broken tree branches should be removed immediately. But save any major removal of leaves and branches for when conditions improve to avoid further weakening an already stressed tree.
Can flooded fruits, vegetables, and other crops still be eaten? Goltz said, “If the part you’re eating touches the water, then it’s probably hazardous, even if washed or cooked.” “That is because in addition to bacteria (细菌) from standing water, runoff from nearby gardens, chemicals, and other waste could be present,” Goltz added.
Flooded soil loses nutrients (营养) and can damage the way water flows through it. After dealing with your plants’ needs, turn your attention to the flooded soil and take some actions to make it repaired. Mixing in sand will improve the way water flows through it. If you live in an area that easily floods, there are steps you can take to avoid or lessen future damage, such as growing vegetables in higher areas or raised beds. Or you could direct water away from the plants you care about most.
1. What message can we get from Goltz’s words in paragraph 1?A.A rainbow comes after rain. | B.Never fish in troubled water. |
C.Too much of anything is good for nothing. | D.Always make preparations for a rainy day. |
A.It might harden the soil. | B.It might break struggling roots. |
C.It will add bacteria to the roots. | D.It will remove more oxygen from the plants. |
A.Unsafe. | B.Special. | C.Tasty. | D.Juicy. |
A.Grow high crops. | B.Repair the soil. |
C.Protect the plants. | D.Build an ecosystem. |
【推荐3】Nowadays, many parents are so busy that they seldom have family meals with their children. But this is wrong.
A Harvard study found that families that eat together are twice as likely to eat their five servings of fruits and vegetables a day as families who don't eat together. Families also eat less fried food when they eat together. Finally, children who regularly eat with family have diets higher in fiber, calcium, iron, and vitamins B6, B12, C and E.
During family meals, parents can set a good example of healthy eating that children may follow. They also display polite table manners. Family meals teach children important skills.
When a family eats together, kids can learn about nutrition and healthy eating. In many studies of schoolaged children, those who eat family meals have a higher level of nutrition knowledge.
When a family eats together, kids learn about food safety, like hand washing before eating.
Children who have company at meals are slimmer than those who eat alone. That's because they eat less, eat more slowly, and talk more. This is a good way to deter obesity in children.
Family meals can help children build vocabulary. Studies showed kids who ate with their families performed better at school and had a broader vocabulary. Family meals offer an opportunity for conversations where kids learn vocabulary—building words to help them read and communicate better.
Children gain a better sense of belonging within the family when they eat together with their parents at home. Family meals offer a time for a family to come together as a group and develop a feeling of belonging. That sense of belonging leads to better selfesteem.
In conclusion, family meals are very important.
1. The writer wants to tell us that .A.eating together with family is a good chance to teach children |
B.it's more advantageous for children to eat with their families |
C.it's desirable for children to eat more regularly |
D.enjoying family meals is equal to eating a big and delicious dinner |
A.Having a company meal is easy to become fatter and fatter. |
B.In the mealtime, parents should set a good example of healthy eating. |
C.Family meals can help children with a higher level of nutrition knowledge. |
D.Family meals can make children form the good habit of eating. |
A.Find. | B.Replace. |
C.Prevent | D.Improve. |
A.Why family is important to kids. | B.How to eat in a healthy way. |
C.How to raise children well. | D.Why family meals are important. |
【推荐1】A lot of people ask this question: “Why is body language so important?” Studies have shown that in the process of communication, non-verbal expression has 65% to 93% more influence than actual text. This means that “how to say” is more important than “what to say”. Of course, this does not mean that you don’t need to do preparation for your interviews, nor does it mean that you can take any short cuts. On the contrary, this means that you have more things to pay attention to and prepare for.
In the real workplace, body language is much more important than you think. Without proper body language, you may find yourself trapped in a circle where you can’t integrate with the external environment, not to mention the difficulties in the absence of body language in the workplace.
“People can often make inferences from actions, and the results of these inferences directly affect lives: for example, who will be employed and who will be promoted.” Academician Amy Cuddy said in a TV talk show. She also said that “Our body language will also affect our perception of ourselves. When you try to make more authoritative actions, your brain will inadvertently receive signals and actually create an idea that you are more authoritative, so that you have more confidence in yourself.”
Therefore, before interviews or important meetings, try not to lean on any object or have a hunched back. Instead, you should try to keep your body relaxed. You can even stand with a relatively authoritative posture—of course, you may need to do these things in the bathroom or places where no one could see you.
Body language plays a crucial role in your job interviews, careers, and everyday life. Paying attention to body language could make strong impacts on your behavior, which could help you achieve better results. So, every time you are nervous or feel that you can’t do it, stretch your body, smile, and tell yourself “Fake it till you become it!”
1. Which of the following statement is TRUE according to Paragraph 1?A.What we say in interviews is not so important. |
B.We should set a high value on body language. |
C.Practicing body language is a short cut to success. |
D.Body language carries 93% of conversation messages. |
A.It makes us look more authoritative. | B.It decides whether we are promoted. |
C.It influences people’s impression of us. | D.It helps people understand who we are. |
A.Bent forward. | B.Tied behind. | C.Straightened up. | D.Broken down. |
A.viewers of a TV talk show | B.body language researchers |
C.working adults to be promoted | D.new arrivals in the workplace |
【推荐2】After years of debate, gray wolves were reintroduced to Yellowstone National Park. Fourteen wolves were caught in Canada and moved to the park. By 2016, the Yellowstone wolf population had grown to more than 170.
Gray wolves once were seen here and there in the Yellowstone area and other parks of the United States, but they were gradually displaced by human development. By the 1920s, wolves had disappeared from the Yellowstone area. They went farther north into the deep forests of Canada, where there were fewer humans around. The disappearance of the wolves had many unexpected results. Deer and elk populations — major food sources (来源) for the wolf — grew rapidly. These animals ate large amounts of plants, which reduced plant diversity in the park. With the disappearance of gray wolves, coyote (草原狼) populations also grew quickly. The coyotes killed a great number of red foxes in the park, and completely drove away the park’s beavers (河狸).
As early as 1966, biologists asked the government to consider reintroducing wolves to Yellowstone Park. They hoped that wolves would be able to control the elk and coyote problems. Many farmers were against the plan because they feared that wolves would kill their farm animals or pets.
The government spent nearly 30 years coming up with a plan to reintroduce the wolves. The U. S. Fish and Wildlife Service carefully monitors and manages the wolf packs in Yellowstone. Today, the debate continues over how well the gray wolf is fitting in at Yellowstone. Elk, deer, and coyote populations are down, while beavers and red foxes have made a comeback. The Yellowstone wolf project has been a valuable experiment to help biologists decide whether to reintroduce wolves to other parts of the country as well.
1. What is the text mainly about?A.Wildlife research in the United States. |
B.Plain diversity in the Yellowstone area. |
C.The reintroduction of wolves to Yellowstone Park. |
D.A war between American farmers and gray wolves. |
A.Killed one by one. | B.Separated from relatives. |
C.Followed secretly. | D.Forced to move out. |
A.More people moved into the park. | B.The number of deer increased fast. |
C.Red foxes ate too many plants. | D.Beavers in the park were all killed. |
A.Positive. | B.Uncaring. | C.Negative (反对). | D.Doubtful. |
【推荐3】We humans have always been obsessed with reaching higher, building taller, and touching the sky. In effect, we have been building towers and buildings each taller than the other. Today, we will look at four of the tallest buildings in the world.
Burj Khalifa
Since it opened on January 4, 2010, the Burj Khalifa has been the tallest building in the world. The United Arab Emirates broke world records in the 21st century for building a needle-like, 162 story skyscraper in Dubai. A public observation deck called “At the Top” is located on the 124th floor. The top floor is home to a private VIP club, closed to anyone except members.
Taipei 101
Featured in many videos, the tallest building in Taipei, China, is famous for its unique shape and awesome fireworks display every year. It houses lots of hotels, offices, apartments, and an observatory deck. There’s an outdoor round observatory square on the 91st floor of the building, at 392m above the ground, it’s now the third highest open-air observation deck in the world.
Shanghai World Financial Centre
The Shanghai World Financial Centre, is a soaring glass skyscraper with a distinctive opening at the top in Pudong District, Shanghai, China. The construction of this building began in 1997, but due to the crisis in Southeast Asia, it temporarily halted and resumed in 2003. Its final height is 492 metres and has 101 floors.
International Commerce Centre (ICC)
The ICC building, completed in 2010 in West Kowloon, is the tallest building in Hong Kong, China, and one of the world’s tallest skyscrapers at 484 metres. Original plans were for an even taller building, but zoning laws prohibited the construction of buildings higher than the surrounding mountains. The design of the skyscraper was revised (修改) and plans for a pyramidal-shaped top were abandoned.
1. What do Burj Khalifa and Taipei 101 have in common?A.They have observatory decks. |
B.They are open for half a day. |
C.They are famous for their unique shapes. |
D.They have the same number of floors. |
A.Shanghai World Financial Centre. |
B.Burj Khalifa. |
C.International Commerce Centre. |
D.Taipei 101. |
A.There’s an outdoor round observatory square on the 92nd floor of Taipei 101. |
B.The top of ICC building is the shape of pyramid. |
C.It took longer time than expected to finish Shanghai World Financial Centre. |
D.Everyone can visit the top floor of Burj Khalifa. |