题型:阅读理解 题类:常考题 难易度:普通
辽宁省沈阳市交联体2018届高三上学期英语期中考试试卷
Can exercise during childhood protect you against memory loss many decades later? Exercise early in life seems to have lifelong benefits for the brain, in rats at least.
“This is an animal study, but it shows that physical activity at a young age is very important—not just for physical development, but for the whole lifelong track of cognitive (认知的) development during ageing,” says Martin Wojtowicz of the University of Toronto, Canada. “In humans, it may delay the appearance of Alzheimer's symptoms (阿兹海默氏症), possibly to the point of preventing them.”
Wojtowicz's team divided 80 young male rats into two equal groups, and placed running wheels in the cages of one group for a period of six weeks. Around four months later-when the rats had reached middle age-the team taught all the rats to connect an electric shock with being in a specific box. When placed in the box, they froze with fear.
Two weeks later, the team tested the rats in three situations: exactly the same box in the same room, the same box with the room arranged differently, and a completely different box in a different room.
The rats without access to a running wheel when they were young now froze the same percentage of times in each of these situations, suggesting they couldn't remember which one was dangerous. But those that had been able to run in their youth froze 40 to 50 percent less in both changed box settings.
“The results suggest the amount of physical activity when we're young, at least for rats, has influence on brain and cognitive health-in the form of better memories-when we're older,” says Arthur Kramer of Northeastern University in Boston, who has found that, in humans, exercise promotes the growth of new brain cells.
Here, sleep experts clear up some of the biggest misunderstandings about sleep they see with their patients, which could weaken your ability to have a night of good sleep.
Myth: {#blank#}1{#/blank#}
The latest research shows that the right amount of sleep may vary from person to person and should leave you feeling energized the next day. I'm a sleep doctor. Take myself for example. {#blank#}2{#/blank#}.
Myth: Don't fall asleep with the TV on.
I've cured more people suffering from sleep problems than you can imagine by telling people it's OK to fall asleep with the TV on. {#blank#}3{#/blank#}Control the watching time so it doesn't affect your sleep later in the night.
Myth: You can catch up on lost sleep on the weekend.
{#blank#}4{#/blank#} A Harvard study found that even if you sleep for an extra 10 hours on the weekend to make up for only sleeping six hours a night for two weeks, those extra hours won't improve your reaction times or ability to focus. Plus, sleeping late throws off your biological clock, which can lead to obesity, diabetes, and heart disease.
Myth: Alcohol can help you rest easy.
{#blank#}5{#/blank#} Alcohol may relax you so you nod off quicker, but studies show you'll wake up more and get less of deep sleep you need to feel rested.
A. You need 8 hours' sleep a night. B. A lack of sleep can cause anxiety. C. We take unscheduled naps during the weekend. D. I've been a 6.5-hour sleeper my entire adult life. E. Many people can't turn off their brains, but watching TV helps. F. People commonly use alcohol to fall asleep, but it doesn't work. G. You can't make up for too little sleep by sleeping more at weekends. |
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