It is a question people have been asking for ages.Is there a way to turn back the aging process？
For centuries，people have been looking for a "fountain of youth".The idea is that if you find a magical fountain，and drink from its waters，you will not age.
Researchers in New York did not find an actual fountain of youth，but they may have found a way to turn back the aging process.It appears the answer may be hidden right between your eyes，in an area called the hypothalamus（下丘腦）.The hypothalamus is part of your brain.It controls important activities within the body.
Researchers at New York's Albert Einstein College of Medicine found that hypothalamus neural（神經(jīng)的）stem cells also influence how fast aging takes place in the body.
What are stem cells？They are simple cells that can develop into specialized cells，like blood or skin cells.Stem cells can also repair damaged tissues and organs.
Dongsheng Cai is a professor at the Albert Einstein College of Medicine.He was the lead researcher in a study on aging in mice.He and his team reported their findings in the journal Nature，Cai explained when hypothalamus function is in decline，particularly the loss of hypothalamus stem cells，and this protection against the aging development is lost.jye.ai eventually leads to aging.
Using this information，the researchers began trying to activate，or energize，the hypothalamus laboratory mice.They did this by injecting the animals with stem cells，Later，the researchers examined tissues and tested for changes in behavior.They looked for changes in the strength and coordination（協(xié)調(diào)）of the animals muscles.They also studied the social behavior and cognitive ability of the mice.The researchers say the results show that the treatment slowed aging in the animals，Cai says injecting middle-aged mice with stem cells from younger mice helped the older animals live longer.
But these results were just from studying mice in a laboratory.If the mice can live longer，does that mean people could have longer lives？The next step is to see if the anti-aging effects also work in.
（1）In Paragraph 2，a "fountain of youth" is mentioned to AA.
A．introduce the main topic
B．show a hidden secret
C．describe scientists research
D．recommend a way to stay young
（2）Aging takes place in the body when CC.
A．stem cells develop into specialized cells
B．there are important activities within the body
C．hypothalamus neural stem cells fail to protect against aging
D．the hypothalamus fails to repair damaged tissues and organs
（3）What do we know about the researchers at Albert Einstein College of Medicine from the text？ BB
A．They did experiments to see how stem cells work.
B．They studied mice to find their connection with humans.
C．They have found a possible way to slow the aging progress.
D．They have found no changes in mice's behavior during the experiment.
（4）What will the researchers probably do next？ DD
A．They will help some animals live longer.
B．They will announce the fountain of youth doesn't exist.
C．They will develop products to help people live a longer life immediately.
D．They will do research to see if what they have found in mice will apply to humans.
【答案】A；C；B；D
【解答】
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發(fā)布：2024/5/27 14:0:0組卷：1引用：1難度：0.5
相似題
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1．Rainforests provide much of the world's oxygen.People have been trying to protect them for years.But another type of forest，the cloud forest，is just as important to humans.
These forests are at the tops of mountains，generally near the equator （赤道）.These wet，wooded mountaintops are mainly in African and Central and South American countries.They are called "cloud forests" because their height allows for the formation of clouds among the trees.The trees in these forests pull water out of the clouds.The water gathers on the leaves and falls into small rivers below，which flow into towns at the bottom of the mountain.The yearly rainfall in these areas is about 180 centimetres.Cloud forests can pull in up to 60 percent of that.The water is important to the plants and the people in the area.It helps them survive.
Cloud forests are also home to countless species of plants that can't be found anywhere else.One small cloud forest has as many types of plants as there are in all of Europe.In fact，there are so many that scientists haven't made a complete list of them yet.
These forests are being destroyed at increasing speed.Trees are being cut down，and roads are being built in their place.Some people have a goal to get government money to protect the forests.But they have had little success so far.Another way is to take the place of the destroyed plants with new ones.That，too，has been difficult because the plants are so special.There's plenty of work to be done，but saving the cloud forests is still possible with creative solutions.
（1）Where can you probably find cloud forests？
A．In North America.
B．Far from the equator.
C．In an African country.
D．At the foot of mountains.
（2）How much rainfall is pulled in by the cloud forests in those areas every year？
A．About 60 cm.
B．About 108 cm.
C．About 180 cm.
D．About 300 cm.
（3）What is the main idea of paragraph 3？
A．Europe is short of plant types.
B．Scientists are working on a list.
C．Cloud forests are getting smaller.
D．Cloud forests house many plants.
（4）What will be discussed in the following part of the text？
A．Ways to protect cloud forests.
B．Goals of cloud forest protectors.
C．Difficulties in planting new trees.
D．Successes of getting wide support.
（5）Where can we probably find the text？
A．In a storybook.
B．In a travel guide.
C．In a chemistry textbook.
D．In a geography magazine.發(fā)布：2025/1/1 18:0:1組卷：7引用：3難度：0.5 -
2．Photo Research "If you want to be a better photographer，stand in front of better stuff." Photographer Jim Richardson shared it with otjye.airs.He spends a great deal of time doing photo research，looking for great locations to shoot.
Seeing a wonderful place is bread-and-butter photography-it's just part of the job.Getting there is only half of any great photograph's story.The other half is how the photographer prepares to capture the subject once in front of jye.ai.It is believed that groundwork is part of photography，as essential as knowing exposure and lighting or recognizing the decisive moment to take the shot.Research sounds like a boring task for many photographers，while for others digging into a subject in advance is part of the pleasure.
Philosophically，photographers seem to divide along that line.On one side are those who desire only to be in the moment.On the other side are the planners.They would never dream of going out the door without a full list of how they're going to approach the shoot.Actually，there is a third group nowadays.They just take photos of the whole scene and do all the creative work in Photoshop after the event.Most photographers do both：research carefully to prepare their schedule and then act in the moment once on site.
Photographers should do a lot of research in order to get ready for a photographic trip.This includes creating a file for each location they are due to visit.They start a file for each place and begin to make a list of the pieces of information.Knowing what the place looks like in advance is invaluable，so it is good to hit several Internet photo sites.Besides clueing them into the photographic possibilities of the location，this can also show what angles have already become overused and which they should therefore avoid.But photographers will also find angles they didn't expect from locations they hadn't imagined.Armed with these they will be better prepared to push the boundaries of what they expect.
"Above all，I'll look for places and events that are seasonal and timeless.I open my mind to what might make a great subject for a picture，" Jim said. "Most travelers tend to think only of places they're visiting，without looking deeper into culture，history or meaning.I try to get in time with the rhythm of the place and in tune with its melody.But most of all I just want to be ready.If I'm ready，I can just about count on being lucky."
（1）What does the underlined word "capture" in Paragraph 2 probably mean？
A．Identify.
B．Record.
C．Arrange.
D．Explore.
（2）What point does the author make about photographers in Paragraph 3？
A．They are unable to decide on the best plan of action.
B．It is possible for them to adopt flexible ways of working.
C．The third group is not as imaginative as some of the others.
D．Some of them refuse to try to understand the way others work.
（3）What is the main idea of Paragraph 4？
A．Sound preparation is a must for a satisfactory photo.
B．One should create photo sites in a photographic trip.
C．Taking photos requires vivid imagination in advance.
D．It is essential to do photo research in central locations.
（4）In the last paragraph，Jim states that.
A．he feels good to visit those historical places
B．he refuses to spend too much time in one place
C．he is careful about choosing the right place to visit
D．he likes to go to places that few people bother to visit發(fā)布：2025/1/1 18:0:1組卷：20引用：3難度：0.7 -
3．The baby is just one day old and has not yet left hospital．She is quiet but alert（警覺(jué)）．Twenty centimeters from her face researchers have placed a white card with two black spots on it．She stares at it carefully．A researcher removes the card and replaces it by another，this time with the spots differently spaced．As the cards change from one to the other，her gaze（凝視） starts to lose its focus - until a third，with three black spots，is presented．Her gaze returns；she looks at it for twice as long as she did at the previous card．Can she tell that the number two is different from three，just 24 hours after coming into the world？
Or do newborns simply prefer more to fewer？The same experiment，but with three spots shown before two，shows the same return of interest when the number of spots changes．Perhaps it is just the newness？When slightly older babies were shown cards with pictures of objects（a comb，a key，an orange and so on），changing the number of objects had an effect separate from changing the objects themselves．Could it be the pattern that two things make，as opposed to three？No again．Babies paid more attention to squares moving randomly on a screen when their number changed from two to three，or three to two．The effect even crosses between senses．Babies who were repeatedly shown two spots became more excited when they then heard three drumbeats than when they heard just two；likewise（同樣地） when the researchers started with drumbeats and moved to spots．
（1）The experiment described in Paragraph 1 is related to the baby's．
A．sense of hearing
B．sense of sight
C．sense of touch
D．sense of smell
（2）Babies are sensitive to the change in．
A．the size of cards
B．the colour of pictures
C．the shape of patterns
D．the number of objects
（3）Why did the researchers test the babies with drumbeats？
A．To reduce the difficulty of the experiment．
B．To see how babies recognize sounds．
C．To carry their experiment further．
D．To keep the babies' interest．
（4）Where does this text probably come from？
A．Science fiction．
B．Children's literature．
C．An advertisement．
D．A science report．發(fā)布：2025/1/1 17:0:1組卷：3引用：3難度：0.5