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第一篇Common-Cold SenseY"的相关试题:
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第一篇
Common-Cold Sense
You can't beat it,but you don't have to join it. Maybe it got the name"common cold"because it's
more common in winter. The fact is,though,being cold doesn't have anything to do with getting one.Colds
are caused by the spread of rhinoviruses（鼻病毒）,and,at least so far,medical science is better at telling
you how to avoid getting one than how to get rid of one.
Children are the most common way cold viruses are spread to adults,because they have more colds than
adults一an average of about eight per year. Why do kids seem so much more easily to get colds than their
parents?Simple.They haven't had the opportunity to become immune to many cold viruses.
There are more than 150 different cold viruses,and you never have the same one twice.Being infected
by one makes you immune to it一but only it.
Colds are usually spread by direct contact,not sneezing or coughing. From another person's hand to
your hand and then to your nose or eyes is the most common route.The highest concentration of cold viruses
any where is found under the thumbnails of a boy,although the viruses can survive for hours on skin or other
smooth surfaces.
Hygiene is your best defense.Wash your hands frequently,preferably with a disinfectant soap,
especially when children in your household have colds.
But even careful hygiene won't ward off every cold.So,what works when a coughing,sneezing,runny
nose strikes?
The old prescription of two aspirins,lots of water,and bed rest is a good place to start.But you'll also
find some of the folk remedies worth trying. Hot mixtures of sugar(or honey),lemon,and water have real
benefits.
When you are having a cold,________.
A.it is always the same kind of cold that you had last time
B.it may be the same kind of cold that you had last time
C.it is certainly not the same kind of cold that you had last time
D.it is probably not the same kind of cold that you had last time
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Common-cold Sense
You can't beat it,but you don't have to join it.Maybe it got the name"common cold"because it's more common in winter.The fact is,though,being cold doesn't have anything to do with getting one.Colds are caused by the spread of rhinoviruses,and,at least so far,medical science is better at telling you how to avoid getting one than how to get rid of one.
Children are the most common way cold viruses are spread to adults,because they have more colds than adults-an average of about eight per year.Why do kids seem so much more easily to get colds than their parents?Simple.They haven't had the opportunity to become immune to many cold viruses.
There are more than 150 different cold viruses,and you never have the same one twice.being infected by one makes you immune to it-but only it.
Colds are usually spread by direct contact,not sneezing or coughing.From another person's hand to your hand and then to your nose or eyes is the most common route.The highest concentration of cold viruses anywhere is found under the thumbnails of a boy,although the viruses can survive for hours on skin or other smooth surfaces.
Hygiene is your best defense.Wash your hands frequently,preferably with a disinfectant soap,especially when children in your household have colds.
But even careful hygiene won't ward off every cold.So,what works when a coughing,sneezing, runny nose strikes?
The old prescription of two aspirins,lots of water,and bed rest is a good place to start.But you'll also find some of the folk remedies worth trying.Hot mixtures of sugar(or honey),lemon,and water have real benefits.
When one is having a cold,he may often have all the following symptoms EXCEPT______.
A.coughing
B.sneezing
C.having a runny nose
D.having a stomachache
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第一篇
Can Gene Technology Make Human Smarter?
Almost everyone wants to get smarter. To achieve that,some choose to do exercise,others choose to take in more nutritions good for brains.Princeton neurobiologist Joseph Z.Tsien possibly found a different way to make it. In September he announced that he'd built a better mouse by altering a gene that affects learning and memory.A similar process of gene manipulation might conceivably be used one day to boost intelligence in humans.
The key of this technology lies in a feature of brain cells called the NMDA receptor,which Tsien likens to a cylindrical tube or window that mediates the flow of information.When the window is open,chemicals called neurotransmitters flow through easily and memory is registered and stored. But as organisms mature,the window begins to close.(This may explain why children lose their facility for learning new languages when they reach sexual maturity and why some people suffer memory loss as they age.)
Tsien also found out that the receptor worked more efficiently if it is teamed with the gene NR2B,so he introduced extra NR2B genes into a batch of fertilized mouse eggs.In a normal mouse,the memory window is open for just 150-thousandths of a second.In Tsien's specially engineered mice,the window opens for 250-thousandths of a second,long enough to make a remarkable difference in memory retention.When he pitted his mice against common mice,they won paws down.Ordinary mice could recognize a Lego block for 12 hours,but smart mice could remember the block for up to three days."That's a profound enhancement,"Tsien says.
Can this technology be applied to humans?Maybe,but genetic engineering will have to make some extraordinary advances first. And some thorny ethical issues will have to be resolved. Mean-while,Tsien promises to keep his furry little geniuses locked up in a lab,far from your larder. "Otherwise,"he says,"you might need a smart cat or a smart mousetrap to catch them."
What problems must be solves before this technology is applied to human?
A:Gene must be conceivably manipulated.
A.Genetic engineering will have to make some extraordinary advances first and some thorny ethical issues will have to be resolved.
B.NMDA receptor is teamed with the gene NR2
C.
D.The smart nice must be locked up in a lab.
