Our solar system might be crazier than we once thought.Scientists say that deep within Uranus（天王星） and Neptune（海王星）it rains diamonds.
On Earth，diamonds form under extreme heat and pressure.The inside of Uranus and Neptune also has high temperatures and pressures.What's more，the blue planets are largely made up of icy water and gases such as methane（甲烷）.
So scientists have long believed that deep inside the two planets，the heat and pressure turn the methane into hydrogen（氫）and carbon（碳）.Then diamond rain would form，falling toward the center of the planets.
But no one could prove that this would really work-until now.In a study published recently in the journal Nature Astronomy，scientists say they were able to create this kind of "diamond rain" in a lab，reported The Guardian.
Scientists used high-powered lasers to create pairs of shockwaves through a kind of plastic.The plastic is made from hydrogen and carbon，much like methane.The shockwaves created high pressure and heat，like that inside Uranus and Neptune.
"The experimental time is very short，" Dominik Kraus，lead author of the study，told The Guardian. "That we saw this very clear signature of diamonds was actually very，very surprising."
The diamonds created in the lab were tiny，only a few nanometers（納米）wide.Scientists believe that diamonds would be much larger within Neptune and Uranus.Then they might slowly sink toward the planet's center because of gravity.
（1）What factors are needed to form diamonds？ CC
A．Icy water and gases.
B．Hydrogen and carbon.
C．Extreme heat and pressure.
D．High-powered lasers.
（2）What does the underlined word mean in the last paragraph？ DD
A．Unsuccessful.
B．Natural.
C．Real.
D．Small.
（3）How did scientists prove the theory of forming diamond？ BB
A．By giving examples.
B．By doing experiments.
C．By explaining statistical data.
D．By stating argument.
（4）What can be referred from the text？ BB
A．There are many high-powered lasers in Neptune and Uranus.
B．Scientists long believe that there are diamonds inside Neptune and Uranus.
C．The shockwaves inside Neptune and Uranus crate high pressure and heat.
D．Deep inside Neptune and Uranus could be full of diamonds.
【答案】C；D；B；B
【解答】
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發(fā)布：2024/9/19 9:0:8組卷：5引用：2難度：0.5
相似題
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1．For some people，the warmest memories from childhood come from being read a great story．（1）
It develops children's language skills and increases their ability to succeed in school and，later，work．
A new report by the American Academy of Pediatrics says reading aloud is so important that parents should start as soon as their children are born and continue to read aloud even after their children can read by themselves．They say parents should also point to and talk about pictures in books for infants（嬰幼兒）．（2）
The company Scholastic is fl major U．S．publisher of children's books．Every two years，Scholastic publishes a report on American reading attitudes and habits．The 2015 report says only 31 percent of children in the U．S．read a book for fun almost every day．
（3）One is simply to have books in the home．Elizabeth Lyttleton，the mother of three，is lucky．Her mother once wrote and illustrated children's books，so the family always have plenty to read．She says all her children learn from books-but in different ways．（4）Researchers from the Scholastic company found that 80%of children surveyed-of all ages-say they love being read to．And children ages 6 to 11 whose parents do not read to them anymore say they miss it．
（5）Of all the six to 17-year-olds in the Scholastic study，more than 90%said their favorite books are the ones they chose for themselves．
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B．Scholastic also identifies some ways to develop a love of reading in a child．
C．A book does not have to be serious to be good for kids．
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E．Do children still read for fun？
F．Another way to develop a reading habit in children is to read to them．
G．But reading to children does more than create warm memories．發(fā)布：2025/1/1 13:30:1組卷：13引用：7難度：0.7 -
2．Chinese students always complain that they're under great pressure and don't get enough sleep.But they may be surprised to learn that they're much luckier than their peers（同齡人）in South Korea and Japan，according to a recently published report，conducted by Shanghai Academy of Social Sciences on the physical and mental health of senior high school students in the three Asian countries.
According to the study among nearly 6，000 high school students in the three countries，Chinese students are the tallest but poorest in physical fitness.Chinese students are on average 168.17cm，compared with 167.61cm for South Korean students and 164.70cm for Japanese students.Chinese students asked for sick leave more than students in other countries.About 72 percent of Korean students never asked for sick and injury leave during high school，compared to 53 percent for Japanese students and 45 percent for Chinese students.Moreover，Chinese students drink alcohol and smoke earlier than Korean and Japanese students.Around 70 percent of Chinese students have drunk alcohol，compared to 50 percent for Korean and Japanese students.
According to the survey，Japanese and South Korean students suffer more pressure than their Chinese peers.Statistics show 16 percent of students in China said they experienced mental pressure often over the past year，while the numbers in Japan and South Korea were 33 percent and 47 percent respectively.Their worries come from "study"，"future after graduation"， "friendships" and "relationship with their parents".To go with stress，57.9 percent of Korean students sleep the least，less than six hours a day，compared with 46.6 percent of Japanese students and 30 percent of Chinese students.
More Chinese students were satisfied with their physical appearance，double that of students in the survey from Japan and South Korea.The report said that over half of students in South Korea had tried to lose weight in the past year，while in China the figure was only 22 percent.In measures of self-worth，such as "I think I am valuable" and "I think I am successful"，"I can complete many things"， "I won't give up to failure，" Chinese students showed greater self-confidence than students in Japan and South Korea.
（1）What's the main idea of the second paragraph？
A．Chinese students ask for sick leave most often.
B．Chinese students drink most alcohol and smoke earliest.
C．Japanese students ask for least sick leave.
D．Chinese teenagers are tallest，but most unhealthy.
（2）It can be inferred from the passage that.
A．Chinese students are confident in themselves and luckier
B．Chinese students are luckiest，yet most unsuccessful
C．Japanese students are most stressed
D．South Korean students sleep the least
（3）What does the underlined word "that" refer to？
A．the height
B．the number
C．the weight
D．the appearance
（4）The worries that causes students to be stressed come from the following factors EXCEPT.
A．study and career
B．friendships
C．physical appearance
D．family relationship發(fā)布：2025/1/1 16:0:1組卷：0引用：3難度：0.5 -
3．Paying ﹩25，000 to get your pet cloned might sound attractive，if you have the money and can't imagine life without your pet.
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What's most important to consumers is the product.Your clone is a twin of your former pet，but it won't necessarily look or act like the original.They may have different colors and you don't get your money back.Even the companies admitted in New York Times "You can clone the look of a dog，but you can't clone the soul."
（1）Why did the author mention Dolly the sheep？
A．To ensure the safety of cloning.
B．To show that it is easy to clone sheep.
C．To prove the technology has a long history.
D．To tell readers the method used to clone their pets.
（2）What can we know about cloning a pet？
A．Your pet can be brought back to life.
B．The charge of pet cloning is ﹩1-2000.
C．Your new pet will have a parent when cloned.
D．The company will refund you if you give up halfway.
（3）What do the companies' words in the last paragraph mean？
A．Cloning is a moral issue.
B．The future of cloning is unclear.
C．The technology of cloning is not perfect.
D．Yon won't get the exact copy of the former one.
（4）Where is the text most likely from？
A．A travel guide.
B．A newspaper.
C．A science fiction.
D．A textbook.發(fā)布：2025/1/1 16:0:1組卷：19引用：4難度：0.5
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