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共用题干
Batteries Built by Viruses
What do chicken pox,the common cold,the flu,and AIDS have in common?They're all diseases caused by viruses,tiny microorganisms that can pass from person to person. It's no wonder that when most people think about viruses,finding ways to steer clear of viruses is what's on people's minds.
Not everyone runs from the tiny disease carriers,though. In Cambridge,Massachu- setts,scientists have discovered that some viruses can be helpful in an unusual way. They are putting viruses to work,teaching them to build some of the world's smallest rechargeable batteries.
Viruses and batteries may seem like an unusual pair,but they're not so strange for engi-neer Angela Beicher,who first came up with the idea. At the Massachusetts Institute of
Technology(MIT)in Cambridge,she and her collaborators bring together different areas of science in new ways.In the case of the virus-built batteries,the scientists combine what they know about biology,technology and production techniques.
Beicher's team includes Paula Hammond,who helps put together the tiny batteries,and
Yet-Ming Chiang,an expert on how to store energy in the form of a battery.“We're working on things we traditionally don't associate with nature,”says Hammond.
Many batteries are already pretty small. You can hold A,C and D batteries in your hand. The coin-like batteries that power watches are often smaller than a penny. However, every year,new electronic devices like personal music players or cell phones get smaller than the year before. As these devices shrink,ordinary batteries won't be small enough to fit in-side.
The ideal battery will store a lot of energy in a small package. Right now,Belcher's model battery,a metallic disk completely built by viruses,looks like a regular watch battery. But inside,its components are very small一so tiny you can only see them with a powerful microscope.
How small are these battery parts?To get some idea of the size,pluck one hair from your head. Place your hair on a piece of white paper and try to see how wide your hair is一 pretty thin,right?Although the width of each person's hair is a bit different,you could probably fit about 10 of these virus-built battery parts,side to side,across one hair. These micro-batteries may change the way we look at viruses.
Which of the following is true of Belcher's battery mentioned in paragraph 6?
A: It is made of metal.
B: It is a kind of watch battery.
C: It can only be seen with a microscope.
D: It is a metallic disk with viruses inside it.
共用题干
Travel Across Africa
For six hours we shot through the barren(荒芜的)landscape of the Karoo desert in
South Africa. Just rocks and sand and baking sun. Knowing our journey was ending,Daniel and I just wanted to remember all we had seen and done. He used a camera. I used words. I had already finished three notebooks and was into the fourth,a beautiful leather notebook I'd bought in a market in Mozambique.
Southern Africa was full of stories and visions.We were almost drunk on sensations,the roaring(咆哮)of the water at Victoria Falls, the impossible silence of the Okavango Delta in Botswana.
And then the other things:dogs in the streets,whole families in Soweto living in one room,a kilometre from clean water.
As we drove towards the setting sun,a quietness fell over us. The road was empty一we hadn't seen another car for hours.And as I drove,something caught my eye,something moving close enough to touch them,to smell their hot breath. I didn't know how long they had been there next to us.
I shouted to Dan:“Look!”But he was in a deep sleep,his camera lying useless by his feet. They raced the car for a few seconds,then disappeared far behind us,a memory of he- roic forms in the red landscape.
When Daniel woke up an hour later I told him what had happened.
”Wild horses?”he said.”Why didn't you wake me up,Sophia?”
”I tried. But they were gone after a few seconds.”
”Are you sure you didn't dream it?”
”You were the one who was sleeping!”
”Typical”,he said.”The best photos are the ones we never take.”
We checked into a dusty hotel and slept the sleep of the dead.
Daniel and Sophia saw a lot of wonderful things.
A: Right
B: Wrong
C: Not mentioned
共用题干
Wide World of Robots
Engineers who build and program robots have fascinating jobs. These researchers tinker(修补)with ma-
chines in the lab and write computer software to control these devices."They're the best toys out there,"
says Howie Choset at Carnegie Mellon University in Pittsburgh.Choset is a roboticist,a person who designs,
builds or programs robots.
When Choset was a kid,he was interested in anything that moved-cars,trains,animals.He put motors
on Tinkertoy cars to make them move.Later,in high school,he built mobile robots similar to small cars.
Hoping to continue working on robots,he studied computer science in college.But when he got to
graduate school at the California Institute of Technology in Pasadena,Choset's labmates were working on
something even cooler than remotely controlled cars:robotic snakes.Some robots can move only forward,
backward , left and right. But snakes can twist(扭曲)in many directions and travel over a lot of different
types of terrain(地形)."Snakes are far more interesting than the cars,"Choset concluded.
After he started working at Carnegie Mellon,Choset and his colleagues there began developing their own
snake robots.Choset'5 team programnied robots to perform the same movements as real snakes,such as
sliding and inching forward.The robots also moved in ways that snakes usually don't,such as rolling.
Choset's snake robots could crawl(爬行)through the grass ,swim in a pond and even climb a flagpole.
But Choset wondered if his snakes might be useful for medicine as well. For some heart surgeries,the
doctor has to open a patient' s chest ,cutting through the breastbone. Recovering from these surgeries can be
very painful. What if the doctor could perform the operation by instead making a small hole in the body and
sending in a thin robotic snake?
Choset teamed up with Marco Zenati,a heart surgeon now at Harvard Medical School ,to investigate the
idea. Zenati practiced using the robot on a plastic model of the chest and they tested the robot in pigs.
A company called Medrobotics in Boston is now adapting the technology for surgeries on people.
Even after 15 years of working with his team's creations,"I still don't get bored of watching the motion
of my robots,"Choset says.
Snake robots could move in only four directions.
A: Right
B: Wrong
C: Not mentioned
共用题干
第一篇
Almost Human?
Scientists are racing to build the world's first thinking robot.This is not science fiction:
some say they will have made it by the year 2020.Carol Packer reports.
Machines that walk,speak and feel are no longer science fiction.Kismet is the name
of an android(机器人)which scientists have built at the Massachusetts Institute of
Technology(MIT).Kismet is different from the traditional robot because it can show
human emotions.Its eyes,ears and lips move to show when it feels happy,sad or bored.
Kismet is one of the first of a new generation of androids一robots that look like human
beings一which can imitate human feelings.Cog,another android invented by the MIT,
imitates the action of a mother. However,scientists admit that so far Cog has the mental
ability of a two-year-old.
The optimists(乐观主义者)say that by the year 2020 we will have created humanoids
(机器人)with brains similar to those of an adult human being. These robots will be
designed to look like people to make them more attractive and easier to sell to the public.
What kind of jobs will they do?In the future,robots like Robonaut,a humanoid invented by
NASA,Will be doing dangerous jobs,like repairing space stations.They will also be doing
more and more of the household work for us.In Japan,scientists are designing androids
that will entertain us by dancing and playing the piano.
Some people worry about what the future holds:will robots become monsters(怪物)?
Will people themselves become increasingly like robots?Experts predict that more and more
people will be wearing micro-computers,connected to the Internet,in the future.People
will have micro-chips in various parts of their body,which will connect them to a wide variety
of gadgets(小装置).Perhaps we should not exaggerate(夸大)the importance of
technology,but one wonders whether,in years to come,we will still be falling in love,
and whether we will still feel pain.Who knows?
In the future robots will also
A:explore space.
B:entertain people.
C:move much faster.
D:do all of the housework.
共用题干
第二篇
Crystal Ear
One day a friend asked my wife Jill if I wanted a hearing aid."He certainly does,"
replied Jill.After hearing about a remarkable new product,Jill finally got up the nerve to
ask me if I'd ever thought about getting a hearing aid."No way,"I said."It would make me
look 20 years older.""No,no,"she replied."This is entirely different.It's Crystal Ear!"
Jill was right. Crystal Ear is different一not the old-styled body worn or over-the-ear aid,
but an advanced personal sound system so small that it's like contacts(隐形眼镜)for your
ears.And Crystal Ear is super-sensitive and powerlul,too.You will hear sounds your ears
have been missing for years.Crystal Ear will make speech louder,and the sound is pure
and natural.
I couldn't believe how tiny it is.It is smaller than the tip of my little finger and it's almost
invisible when worn. There are no wires,no behind-the-ear device. Put it in your ear and
its ready-to-wear mold(形状)fits comfortably. Since it's not too loud or too tight , you
may even forget that you're wearing it!Use it at work or at play.And if your hearing
problem is worse in certain situations,use Crystal Ear only when you need it.
Hearing loss,which occurs typically prior to teenage years,progresses throughout
one's lifetime.Although hearing loss is now the world's number one health problem,nearly
90 percent of people suffering hearing loss choose to leave the problem untreated.For
many millions,treating hearing loss in a conventional way can involve numerous office
visits,expensive testing and adjustments to fit your ear. Thanks to Crystal Ear,the
"sound solution"is now convenient.Almost 90 percent of people with mild hearing loss,
and millions more with just a little hearing drop-off(下降),can be dramatically helped with
Crystal Ear. Moreover,its superior design is energy-efficient,so batteries can last
months.Crystal Ear is now available to help these people treat their hearing loss with a
small hearing amplifier(放大器).
According to the passage,hearing loss is
A:only a minor health problem.
B:the world's most common health problem.
C:merely a teenage disease.
D:an incurable disease.