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题型:阅读理解-阅读单选 难度:0.65 引用次数:304 题号:14886765

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.
2. According to the passage, lingcod’s teeth are replaced ___________.
A.every 10 daysB.to better hunt for food
C.faster in the oral jawD.with bigger and sharper ones
3. What does the underlined word “shed” in the last paragraph probably mean?
A.Repair.B.Sharpen.C.Lose.D.Examine.
4. What is the purpose of writing this passage?
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.
【知识点】 科普知识 说明文

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文章大意:这是一篇说明文。文章介绍了一项研究表明:女性比男性哭得多,介绍了其原因以及表现。

【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
2. Women would feel most ashamed when crying in front of ______.
A.husbandsB.friendsC.workmatesD.strangers
3. How does the passage present the findings of the study?
A.By making a comparison.B.By giving typical examples.
C.By using the experts’ words.D.By offering facts and opinions.
4. What is the best title for the text?
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
2022-07-11更新 | 114次组卷
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【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?
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4. What are people advised to do in the last paragraph?
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2023-10-04更新 | 29次组卷
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【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
2. Which of the following statements is NOT true?
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.
3. What does the underlined word “deter” in Paragraph 6 mean?
A.Find.B.Replace.
C.PreventD.Improve.
4. What is the passage mainly about?
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.
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