Even facts “forgotten” by people during a busy day may be retrieved if this is followed by a good night’s sleep.
Researchers from the University of Chicago asked volunteers to remember simple words．Many found their memories letting them down towards the end of the day, but the following morning, those who had slept well could recall much more.
Researchers, writing in the journal Nature, said the brain could “rescue” lost memories during the night.
When the brain is first asked to remember something that memory is laid down in an “unstable” state, meaning that it is possible that it could be lost．At some point, the brain consolidates those it deems important into a “stable”, more permanent state．However, the Chicago researchers suggested that it was possible for a “stable” memory to be made “unstable” again．This would mean that memories could be modified then filed away again in the face of new experiences.
The 12 volunteers tested in the experiment were played words created through a speech synthesizer which were purposely difficult to understand．Initially, the written version of the word  from the audio version only．Tests revealed that the ability to recall the right word tended to tail off as the day ended.
However, when the volunteers were retested after a good night’s sleep, they were able to recall some words that they had “ forgotten” the previous evening.
Dr Daniel, one of the study authors, said: “Sleep consolidates memories, protecting them against subsequent interference or decay．Sleep also appears to “recover” or restore memories.” He said: “If performance is reduced by decay, sleep might actively recover what has been lost.”
Dr Karim Nader, from the Department of Psychology in McGill University in Montreal, said: “Memory research is undergoing a transformation---no longer is memory thought to be a hard-writing of the brain, instead it seems to be a process of storage and restorage.”
Sleep helps some memories “mature” and also prunes out unimportant memories.
【小题1】What does the first paragraph implies?

A．A busy day makes people forget things easily.

B．People need a good night’s sleep after a busy day.

C．A good night’s sleep helps memories.

D．A good night’s sleep helps people forget a busy day.

【小题2】The words the 12 volunteers played in the experiment were not ____

A．created through a speech synthesizer

B．hard to understand

C．available at the beginning

D．designed to test people’s ability of understanding

【小题3】According to the passage, memory_____

A．is a hard-writing of the brain

B．is not a process of storage

C．is not a process of restorage

D．will be mature with the help of sleep

【小题4】Which of the following is NOT true?

A．When people first remember something, the memory is in an “unstable state”.

B．The brain will change those important unstable memories into stable.

C．Once the memory become stable, it will never become unstable again.

D．Sleep can protect memories from being harmed.

Even facts “forgotten” by people during a busy day may be retrieved if this is followed by a good night’s sleep.

Researchers from the University of Chicago asked volunteers to remember simple words．Many found their memories letting them down towards the end of the day, but the following morning, those who had slept well could recall much more.

Researchers, writing in the journal Nature, said the brain could “rescue” lost memories during the night.

When the brain is first asked to remember something that memory is laid down in an “unstable” state, meaning that it is possible that it could be lost．At some point, the brain consolidates those it deems important into a “stable”, more permanent state．However, the Chicago researchers suggested that it was possible for a “stable” memory to be made “unstable” again．This would mean that memories could be modified then filed away again in the face of new experiences.

The 12 volunteers tested in the experiment were played words created through a speech synthesizer which were purposely difficult to understand．Initially, the written version of the word  from the audio version only．Tests revealed that the ability to recall the right word tended to tail off as the day ended.

However, when the volunteers were retested after a good night’s sleep, they were able to recall some words that they had “ forgotten” the previous evening.

Dr Daniel, one of the study authors, said: “Sleep consolidates memories, protecting them against subsequent interference or decay．Sleep also appears to “recover” or restore memories.” He said: “If performance is reduced by decay, sleep might actively recover what has been lost.”

Dr Karim Nader, from the Department of Psychology in McGill University in Montreal, said: “Memory research is undergoing a transformation---no longer is memory thought to be a hard-writing of the brain, instead it seems to be a process of storage and restorage.”

Sleep helps some memories “mature” and also prunes out unimportant memories.

What does the first paragraph implies?

       A．A busy day makes people forget things easily.

       B．People need a good night’s sleep after a busy day.

       C．A good night’s sleep helps memories.

       D．A good night’s sleep helps people forget a busy day.

The words the 12 volunteers played in the experiment were not ____

       A．created through a speech synthesizer

       B．hard to understand

       C．available at the beginning

       D．designed to test people’s ability of understanding

According to the passage, memory_____

       A．is a hard-writing of the brain

       B．is not a process of storage

       C．is not a process of restorage

       D．will be mature with the help of sleep

Which of the following is NOT true?

       A．When people first remember something, the memory is in an “unstable state”.

       B．The brain will change those important unstable memories into stable.

       C．Once the memory become stable, it will never become unstable again.

       D．Sleep can protect memories from being harmed.

Even facts “forgotten” by people during a busy day may be retrieved if this is followed by a good night’s sleep.

Researchers from the University of Chicago asked volunteers to remember simple words．Many found their memories letting them down towards the end of the day, but the following morning, those who had slept well could recall much more.

Researchers, writing in the journal Nature, said the brain could “rescue” lost memories during the night.

When the brain is first asked to remember something that memory is laid down in an “unstable” state, meaning that it is possible that it could be lost．At some point, the brain consolidates those it deems important into a “stable”, more permanent state．However, the Chicago researchers suggested that it was possible for a “stable” memory to be made “unstable” again．This would mean that memories could be modified then filed away again in the face of new experiences.

The 12 volunteers tested in the experiment were played words created through a speech synthesizer which were purposely difficult to understand．Initially, the written version of the word  from the audio version only．Tests revealed that the ability to recall the right word tended to tail off as the day ended.

However, when the volunteers were retested after a good night’s sleep, they were able to recall some words that they had “ forgotten” the previous evening.

Dr Daniel, one of the study authors, said: “Sleep consolidates memories, protecting them against subsequent interference or decay．Sleep also appears to “recover” or restore memories.” He said: “If performance is reduced by decay, sleep might actively recover what has been lost.”

Dr Karim Nader, from the Department of Psychology in McGill University in Montreal, said: “Memory research is undergoing a transformation---no longer is memory thought to be a hard-writing of the brain, instead it seems to be a process of storage and restorage.”

Sleep helps some memories “mature” and also prunes out unimportant memories.

What does the first paragraph implies?

       A．A busy day makes people forget things easily.

       B．People need a good night’s sleep after a busy day.

       C．A good night’s sleep helps memories.

       D．A good night’s sleep helps people forget a busy day.

The words the 12 volunteers played in the experiment were not ____

       A．created through a speech synthesizer

       B．hard to understand

       C．available at the beginning

       D．designed to test people’s ability of understanding

According to the passage, memory_____

       A．is a hard-writing of the brain

       B．is not a process of storage

       C．is not a process of restorage

       D．will be mature with the help of sleep

Which of the following is NOT true?

       A．When people first remember something, the memory is in an “unstable state”.

       B．The brain will change those important unstable memories into stable.

       C．Once the memory become stable, it will never become unstable again.

       D．Sleep can protect memories from being harmed.

 When people first walked across the Bering Land Bridge thousands of years ago, dogs were by their sides, according to a study published in the journal Science.

   Robert Wayne of the University of California, Los Angeles, and Jennifer Leonard of the Smithsonian Institute, used DNA material—some of it unearthed by miners in Alaska—to conclude that today’s domestic dog originated in Asia and accompanied the first humans to the New World about 10,000 to 15,000 years ago. Wayne suggests that man’s best friend may have enabled the tough journey from Asia into North America. “Dogs may have been the reason people made it across the land bridge,” said Wayne. “They can pull things, carry things, defend you from fierce animals, and they’re useful to eat.”

   Researchers have agreed that today’s dog is the result of the domestication(驯化) of wolves thousands of years ago. Before this recent study, a common thought about the precise origin of North America’s domestic dog was that Natives domesticated local wolves, the descendents(后代) of which now live with people in Alaska, Canada, and the Lower 48.

   Dog remains from a Fairbanks-area gold mine helped the scientists reach their conclusion. Leonard, an evolutionary biologist, collected DNA from 11 bones of ancient dogs that were locked in permafrost(永冻层) until Fairbanks miners uncovered them in the 1920s. The miners donated the preserved bones to the American Museum of Natural History in New York City, where they remained untouched for more than 70 years. After borrowing the bones from the museum, Leonard and her colleagues used radiocarbon techniques to find the age of the Alaska dogs. They found the dogs all lived between the years of 1450 and 1675 A.D., before Vitus Bering and Aleksey Chirikov who were the first known Europeans to view Alaska in 1741. The bones of dogs that wandered the Fairbanks area centuries ago should therefore be the remains of “pure native American dogs,” Leonard said. The DNA of the Fairbanks dogs would also expose whether they were the descendents of wolves from North America.

   Along with the Fairbanks samples, the researchers collected DNA from bones of 37 dog specimens(标本) from Mexico, Peru, and Bolivia that existed before the arrival of Columbus. In the case of both the Alaska dogs and the dogs from Latin America, the researchers found that they shared the most genetic material with gray wolves of Europe and Asia. This supports the idea of domestic dogs entering the New World with the first human explorers who wandered east over the land bridge.

   Leonard and Wayne’s study suggests that dogs joined the first humans that made the adventure across the Bering Land Bridge to slowly populate the Americas. Wayne thinks the dogs that made the trip must have provided some excellent service to their human companions or they would not have been brought along. “Dogs must have been useful because they were expensive to keep,” Wayne said. “They didn’t feed on mice; they fed on meat, which was a very guarded resource.”

1. The underlined word “remains” is closed in meaning to ______.

A. leftover food     B. animal waste

C. dead bodies    D. living environment

2. According to the study described in Paragraph 4, we can learn that ______.

A. ancient dogs entered North America between 1450 and 1675 AD

B. the 11 bones of ancient dogs are not from native American dogs

C. the bones discovered by the gold miners were from North American wolves

D. the bones studied were not from dogs brought into North America by Europeans

3. What can we know from the passage?

A. Native Americans domesticated local wolves into dogs.

B. Scientists discovered some ancient dog remains in 1920s.

C. Latin America’s dogs are different from North America’s in genes.

D. Ancient dogs entered North America across the Bering Land Bridge.

4. The first humans into the New World brought dogs along with them because ______.

A. dogs fed on mice                    B. dogs were easy to keep

C. dogs helped protect their resources      D. dogs could provide excellent service

5.What does the passage mainly talk about ______.

A. the origin of the North American dogs

B. the DNA study of ancient dogs in America

C. the reasons why early people entered America

D. the difference between Asian and American dogs

 

Even facts “forgotten” by people during a busy day may be retrieved if this is followed by a good night’s sleep.

Researchers from the University of Chicago asked volunteers to remember simple words．Many found their memories letting them down towards the end of the day, but the following morning, those who had slept well could recall much more.

Researchers, writing in the journal Nature, said the brain could “rescue” lost memories during the night.

When the brain is first asked to remember something that memory is laid down in an “unstable” state, meaning that it is possible that it could be lost．At some point, the brain consolidates those it deems important into a “stable”, more permanent state．However, the Chicago researchers suggested that it was possible for a “stable” memory to be made “unstable” again．This would mean that memories could be modified then filed away again in the face of new experiences.

The 12 volunteers tested in the experiment were played words created through a speech synthesizer which were purposely difficult to understand．Initially, the written version of the word  from the audio version only．Tests revealed that the ability to recall the right word tended to tail off as the day ended.

However, when the volunteers were retested after a good night’s sleep, they were able to recall some words that they had “ forgotten” the previous evening.

Dr Daniel, one of the study authors, said: “Sleep consolidates memories, protecting them against subsequent interference or decay．Sleep also appears to “recover” or restore memories.” He said: “If performance is reduced by decay, sleep might actively recover what has been lost.”

Dr Karim Nader, from the Department of Psychology in McGill University in Montreal, said: “Memory research is undergoing a transformation---no longer is memory thought to be a hard-writing of the brain, instead it seems to be a process of storage and restorage.”

Sleep helps some memories “mature” and also prunes out unimportant memories.

1.What does the first paragraph implies?

A．A busy day makes people forget things easily.

B．People need a good night’s sleep after a busy day.

C．A good night’s sleep helps memories.

D．A good night’s sleep helps people forget a busy day.

2.The words the 12 volunteers played in the experiment were not ____

A．created through a speech synthesizer

B．hard to understand

C．available at the beginning

D．designed to test people’s ability of understanding

3.According to the passage, memory_____

A．is a hard-writing of the brain

B．is not a process of storage

C．is not a process of restorage

D．will be mature with the help of sleep

4.Which of the following is NOT true?

A．When people first remember something, the memory is in an “unstable state”.

B．The brain will change those important unstable memories into stable.

C．Once the memory become stable, it will never become unstable again.

D．Sleep can protect memories from being harmed.