今日关键语导读Today"s Key Points
良好的记忆力是学习、工作、生活得以顺利进行的重要保证。那么，良好的记忆力从哪里来呢？记忆力与睡眠的时间长短和深度有着怎样的关系？记忆力能够提高吗？怎么提高？听本文告诉你怎么做。
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Burning the midnight oil before an exam or interview is counterproductive according to research which found that sleep is necessary for memories to be downloaded into the brain.
A good night"s sleep within 30 hours of trying to remember a new task is a prerequisite of having good recall in the weeks ahead， scientists have found.
The research， published in the December issue of Nature Neuroscience， showed that it was the act of sleep， rather than the simple passage of time， that was critical for long-term memory formation.
“It seems that memories normally wash out of the brain unless some process nails them down. My suspicion is that sleep is one of those things that does the nailing down，”said Professsor Stickgold， a sleep researcher at Harvard Medical School who conducted the latest study.
Volunteers in an experiment found it easier to remember a memory task if they were allowed to sleep that night. But for those kept awake， no amount of subsequent sleep made up for the initial loss.
Professor Stickgold"s team trained the 24 people to identify the orientation of three diagonal bars flashed for a sixtieth of a second on a computer screen full of horizontal stripes.
AHalf the subjects were kept awake that night， while the other half slept. Both groups were allowed to sleep for the second and the third nights to make up for any differences in tiredness between the volunteers.Those who slept the first night were significantly and consistently better at remembering the task while the second group showed no improvement despite enjoying two nights of catch-up sleep.
A further study by scientists in Germany showed that memories are laid down in two stages during the night. The first is during the deep， so-called“slow wave”sleep， which usually occurs in the first half of the night.The second and less important stage occurs during periods of dreaming， or“rapid eye movement”.BWhen people are sleep-deprived in the first half of the night， their memory consolidation is almost the same as having no sleep at all.Being deprived of REM sleep was not found to be so detrimental for memory recall but was important in terms of implicit learning， when performance is not relying solely on the ability to remember.
The scientists concluded that a good night"s sleep， with both slow-wave and REM sleep produced the best intellectual performances among their volunteers.
难点重点，一目了然！
长难句解析Sentence Structures
AHalf the subjects were kept awake that night， while the other half slept.
半数被试人员当晚不允许睡觉，而另一半被试人员则睡了。
BWhen people are sleep-deprived in the first half of the night， their memory consolidation is almost the same as having no sleep at all.
当人们前半夜睡不了觉，其记忆力保持程度与没有睡觉者几乎一样。
91.Rock of Ages 多年的顽石
Track 091. MP3
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总词汇量：0405词汇
每篇好演讲都有灵魂！
今日关键语导读Today"s Key Points
一篇意境优美、语言质朴、寓意深刻、启迪思想的文章会令人百读不厌，读罢掩卷反思，方能感悟人生真谛。怎样才能活得有意义，对得起他人和自己，做一个对社会有用的人，请听《多年的顽石》。
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When I came to the farm as a bride， the rock was there， just around the corner of the house.It was an ugly dull orange， about a foot in diameter， and stuck up a couple of inches through the back lawn waiting to trip me.
“Can"t we dig it out？”I asked after I hit full speed with the lawn mower， breaking the blade.
“No， it"s always been there，”my husband said.“It goes down pretty deep， I reckon.”My father-in-law added.“My wife"s family has lived here since the Civil War. No one"s ever got it out.”
So it stayed. My children were born， grew up and went away.My father-in-law died.Some time later， my husband died.
After the mourning， there was the coping-and with a sharpened awareness of my surroundings， because I could change them more easily than my life"s situation. ANow I began to see the yard around me the way a woman sees her house when a company comes unexpectedly.I saw a hundred little sore spots.I began to heal them， one at a time.
I went to the shed and got my shovel. I was going to dig out the rock.
I braced myself for what was to be a long day， perhaps experienced by previous generations who had tried to dislodge the rock. I put on heavy shoes and rolled out my wheelbarrow.If it took the whole day， that rock was going to come out.
Five minutes later the rock was out， about a foot deep， and maybe six inches wider than it looked from the top.
I was stunned. Because the rock had appeared to be large and deep， it was treated as immovable and strong.BI have seen people do this too-and get others to walk carefully around them and assume a depth of character and knowledge solely from demeanor rather than from actual accomplishment.
The orange rock had earned my respect. I couldn"t just dump it behind the barn.So I wheeled it over to the shed， still within sight of the house.It rests there， with vines growing around it.
I still see the rock every day but now as something good in my little landscape. lt"s a reminder that each generation ought to find things out for itself.
难点重点，一目了然！
长难句解析Sentence Structures
ANow I began to see the yard around me the way a woman sees her house when a company comes unexpectedly.
我现在开始以挑剔的眼光审视周围的院子，就像一位女主人在一批客人意外来访时审视她自己一样。
BI have seen people do this too-and get others to walk carefully around them and assume a depth of character and knowledge solely from demeanor rather than from actual accomplishment.
在现实生活中，这样的人比比皆是。他们摆出一副学识渊博、深不可测的面孔，纯粹是装模作样，没有什么真才实学，让人对他们敬而远之。
92.True and False Simplicity真纯粹与假纯粹
Track 092. MP3
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总词汇量：0398词汇
每篇好演讲都有灵魂！
今日关键语导读Today"s Key Points
纯朴，是人生的至高境界。纯朴是无私心灵中一种正直的品质；它与真诚不同，却高于真诚。纯朴是一种适度的中庸。真正的纯朴是灵魂的自由——它能够直视前方道路，没有时间停下来仔细思考脚下的步伐，也不会去回顾已经走过的道路。
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