Scientists have found living organisms (有機(jī)體) that could be 50,000 years old recently.The organisms were found in a hot,but beautiful cave system in Naica,Mexico.These ancient life forms can be seen only with a microscope,which proves they are probably microbes (微生物).
Penelope Boston leads the Astrobiology Institute at NASA,the space agency of the United States.These ancient organisms are able to exist by eating minerals such as iron and manganese.If the findings are confirmed,they will show how microbes can survive in extreme conditions.
Researchers have been studying ancient microbes for nine years.Forty different kinds of microbes and some viruses were found in the underground area this time.The genetic (基因的) structures of these organisms are different from those of their nearest relatives-viruses.That is similar to that humans are genetically different from mushrooms growing in the forest.The caves in Naica are 800 kilometers deep.Before the miners began working in the caves,the area was isolated from the surface and the outside world.
Some of the caves are as big as the large religious centers built during Europe's Middle Ages.There are crystals (晶體) covering the walls.Scientists must wear special clothing to keep cool.And the clothing keeps the crystals safe from human germs or other damage.The researchers could only work for about 20 minutes at a time before they have to go to a room that is 28 degrees Celsius to cool down.
NASA officials would not let Boston share her findings with scientific experts until the last week's announcement.So scientists could not say much about the findings.But Norine Noonan,a biologist at the University of South Florida,said she believed them."Why are we surprised?"Noonan asked,"As a biologist,I would say life on Earth is extremely tough and versatile.""What's more,these organisms are not the oldest life forms on Earth.Scientists published studies about living microbes that may be 500,000 years old several years ago,"she added.
(1)What do these ancient life forms survive on? AA
A.Minerals.
B.Organisms.
C.Viruses.
D.Plants.
(2)What's the author's purpose of mentioning the example of humans and mushrooms? CC
A.To prove the ancient organisms are close to mushrooms.
B.To show the area was once cut off from the outside world.
C.To explain the ancient organisms and viruses are different in genes.
D.To show the ancient organisms found differ from humans in genes.
(3)Why could the researchers only stay for a short time in the caves at a time? AA
A.Because the caves are very hot.
B.Because the caves are full of harmful gases.
C.Because there are some germs in the caves.
D.Because crystals tee damage people's health.
(4)What's the main idea of the passage? CC
A.A beautiful cave system was discovered in Naica.
B.The ancient life forms are too small to be seen.
C.50,000-year-old living organisms were found in Mexico.
D.Researchers find new ways to study living organisms.
【答案】A;C;A;C
【解答】
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發(fā)布:2024/5/27 14:0:0組卷:19引用:1難度:0.5
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1.Scientists say they have created a new device that can turn brain signals into electronic speech.The invention could one day give people who have lost the ability to speak a better way of communicating than current ones.
The device was developed by researchers from the University of California,San Francisco.Their results were recently published in a study in the journal Nature.Scientists created a "brain machine connection" that was set in the brain.The device was built to read and record brain signals that helped control the muscles to produce speech.These include the lips,tongue and jaw.
The study involved five volunteer patients who were being treated for epilepsy (癲癇).The individuals had the ability speak and already had electrodes (電極) set in their brains.The volunteers were asked to read several hundred sentences aloud while the researchers recorded their brain activity.
The researchers used audio recordings to reproduce the vocal (發(fā)聲的) muscle movement which is the key to producing human speech.Future studies will test the technology on people who are unable to speak.
The study reports the reproduced sentences were understandable to hundreds of human listeners asked to write out what they heard.The listeners were able to write out 43 percent of sentences with perfect accuracy.
Edward Chang is a professor of the university's Well Institute.He was a lead researcher on the project.Chang admitted that much more research of the system would be needed to reach the goal of perfectly reproducing spoken language.
(1)Who will probably benefit most from this device?
A.Those unable to hear.
B.Those unable to see.
C.Those unable to speak.
D.Those unable to write.
(2)What do we know about the "brain machine connection"?
A.It could control the muscles.
B.It could produce human speech.
C.It could transform brain signals.
D.It could read and record brain signals.
(3)Which of the following is important for production of human speech?
A.Brain activity.
B.Muscle control.
C.Audio recording.
D.Vocal muscle movement.
(4)In which section of a newspaper may this text appear?
A.Science.
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D.Entertainment.發(fā)布:2024/12/17 1:30:1組卷:9引用:4難度:0.7 -
2.Houses have been getting progressively "smarter" for decades,but the next generation of smart homes may offer what two Case Western Reserve University scientists are calling an "Internet of Ears".
Today's smart home features appliances,entertainment systems,security cameras and lighting,heating and cooling systems that are connected to each other and the Internet.They can be accessed and controlled remotely by computer or smartphone apps.
But a group of electrical engineering and computer science professors in the Case School of Engineering have been experimenting with a new suite of sensors (傳感器).This system would read not only the vibrations (震動(dòng)),sounds and even other movements associated with people and animals in a building,but also any slight changes in the existing electrical field.
While there still maybe a decade or so away,the home of the future could be a building that adjusts to your activity with only a few small,hidden sensors in the walls and floor without the need for monitoring cameras.
"We are trying to make a building that is able to 'listen' to the humans inside," said Ming Chun Huang,an assistant professor in electrical engineering and computer science."We are using principles similar to those of the human ear,where vibrations are picked up and our algorithms (計(jì)算程序) recognise them to determine your specific movements.That's why we call it the 'Internet of Ears'."
"There is actually a constant 60 Hz electrical field all around us,and because people are somewhat conductive,they short out the field just a little," Huang said."So,by measuring the disturbance in that field,we are able to determine their presence,or even their breathing,even when there are no vibrations associated with sound."
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D.What Are Next Smart Homes Like?發(fā)布:2024/12/9 9:30:1組卷:22引用:1難度:0.7 -
3.A new study suggests that dark markings on the planet Mars represent sand —not water.The research in 2015 suggested that lines on some Martian hills were evidence of water.Yet American scientists now say these lines appear more like dry,flows of sand.If water is present,it is likely to be a small amount.Water in liquid form would be necessary for microbial(微生物的) life.
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"I still think that Mars has a great potential for having had life early on in its history," Meyer said. "As long as that's true,we also have a reasonable possibility of life still being on Mars.It just happens to be cryptic or well hidden."
NASA currently has no robotic vehicle—either on Mars or in development—with the ability to climb steep slopes.The lack of such equipment has engineers coming up with ideas like Martian helicopters or planes without pilots.
(1)What do American scientists find on Mars now according to their study?
A.A lot of little life.
B.An amount of water.
C.Some Martian hills.
D.Dark markings are sand.
(2)When do the markings come out?
A.In Martian spring.
B.In Martian summer.
C.In Martian autumn.
D.In Martian winter.
(3)What's Meyer's opinion about having life on Mars?
A.Doubtful.
B.Trustful.
C.Indifferent.
D.Objective.
(4)What does the underlined word "cryptic " in Paragraph 4 mean?
A.Undiscovered
B.Strange.
C.Magical.
D.Icy.發(fā)布:2024/12/3 12:0:1組卷:54引用:3難度:0.7
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