Paragraph 1: Why do we sleep? It can be dangerous to lo awareness of the external world. If nothing el, sleep might em to take away from time that could be spent on productive, or even necessary, activities. But people cannot override indefinitely the desire to sleep; the body shuts down whether we like it or not. There are three general explanations that describe the adaptiveness of sleep: restoration, circadian cycles, and facilitation of learning.
1. The word indefinitely in the passage is clost in meaning to 儿童床十大品牌
A. easily
B. without effects
C. on purpo
D. endlessly
Paragraph 2: The restoration theory of sleep emphasizes that the brain and body need to rest and that sleep allows the body to repair itlf. Indeed, growth hormone's relead during deep sleep, and one of its functions is to facilitate repair of damaged tissue. Additional evidence that sleep is a time of restoration is that people who have engaged in vigorous physical activity, such as running marathons, em to sleep longer. But people sleep even if they spend the day being physically inactive. In addition, it appears that sleep allows the brain to strengthen the body's ability to fight dia.
2. According to paragraph 2, all of the following are considered to be evidence that sleep is needed for the body to repair itlf EXCEPT:
落后英语
A. The body’s resistance to dia is strengthened through sleep.
B. Body tissues are restored by the relea of hormones during sleep.
C. The longer people sleep, the more activity occurs.
D. Sleep occurs whether or not physical activity has taken place.
Paragraph 3: Numerous laboratory studies have examined the effects of sleep deprivation on physical and cognitive performance. Surprisingly, most studies find that two or three days of deprivation have little effect on strength, athletic ability, or cognitive performance on complex tasks. Performing boring or ordinary tasks when sleep deprived, however, is nearly impossible. A brain-imaging study of sleep-deprived people found incread activation of the prefrontal cortex, suggesting that some brain regions may compensate for the effects of deprivation. Over long periods, however, sleep deprivation eventually caus problems with mood and cognitive performance. Indeed, studies using rats have found that extended sleep deprivation compromis the immune system and leads to death. Interestingly, sleep deprivation might rve one very uful purpo, which is helping people overcome depression. Consistent evidence has emerged over the past decade demonstrating that depriving depresd people of sleep sometimes alleviates their depression. This effect appears to occur becau sleep deprivation leads to incread activation of rotonin receptors, which combat depression.
9哭3. Why does the author say “Performing boring or ordinary tasks when sleep deprived, ho
wever, is nearly impossible”?
A. To identify a type of task in which being sleep-deprived for a few days actually does affect physical and cognitive performance
B. To suggest that simple tasks are easier to perform than complex tasks after sleep deprivation
C. To indicate an important finding of a brain-imaging study on the effects of sleep deprivation on the prefrontal cortex 万马奔腾二胡独奏
D. To suggest that physical acts are preformed more easily than cognitive acts after sleep deprivation
4. The word compensate for in the passage is clost in meaning to
A. add to
B. make up for
C. slow down
D. repair
5. The word extended in the passage is clost in meaning to
A. measurable
B. forced
C. occasional
D. lengthened
说话用英语怎么说6. The word Consistent in the passage is clost in meaning to
A. Independent
B. Critical
C. Unvarying
D. Considerable
7. According to paragraph 3, what was one unexpected finding reported by studies investigating sleep deprivation?
A. Sleep deprivation helps people perform better on complex tasks.
B. Sleep deprivation of a few days’ duration does not significantly weaken performance on challenging tasks.
C. Sleep deprivation is more common in people who are physically inactive than it is in active people.
D. Sleep deprivation can sometimes temporarily improve physical abilty.
8. Which of the following can be inferred from the discussion about sleep deprivation in paragraph 3？
qq钱包实名认证A. Short-term sleep deprivation has a negative impact on athletic performance.
B. Short-term sleep deprivation verely harms the immune system.
C. Sleep deprivation can have both positive and negative effects.
