It’ssuchacommoneventthatyouprobablyneveraskedyourselfwh...
问题详情:
It’s such a common event that you probably never asked yourself why you sleep. ___36___. In fact, for sleep researchers, it’s one of the biggest unanswered questions in the field.
Stop and think about it for a second. Why should we sleep? ___37___ . But we sleep every night, even when we have had plenty of rest. There are, no doubt, several different answers to this question, but let’s just consider one general purpose of sleep: ___38___. Human beings are creatures that are normally active during daylight hours, when our senses functions most effectively. ___39___. We can’t see objects well, our color vision is entirely lost, and we don’t have the smelling or hearing sharpness of other animals. So it actually does make sense to have us stay where we are during the dangerous period when night-waking animals are walking here and there. And one sure way to make sure we don’t fall down everywhere and get lost or eaten is to have us not move for seven or eight hours, rising again only when the light is back and our survival chances are better.
It’s not the only reason we sleep. ___40___. Perhaps even the most important one.
A. Is it because we get tired?
B. Should that put human beings in a terrible situation?
C. But from a scientific point of view, this is far from an ordinary matter.
D. But in terms of evolution, it may have been one of the first reasons.
E. Furthermore, if you were designing an animal, would you have it come into long periods of unconsciousness every twenty-four hours?
F. Sleep as a survival approach.
G. At night, humans do rather poorly.
【回答】
CAFGD
知识点:阅读填空
题型:阅读填空
-
下列反应的离子方程式正确的是( )A.在碳**镁溶液中加入足量Ca(OH)2溶液:Mg2++2HCO3-+C...
问题详情:下列反应的离子方程式正确的是( )A.在碳**镁溶液中加入足量Ca(OH)2溶液:Mg2++2HCO3-+Ca2++2OH-=MgCO3↓+CaCO3↓+2H2OB.电解饱和食盐水:C.过量的铁与浓**反应: Fe+6H++3NO3-=Fe3+十3NO2↑+3H2OD.向硫*铝铵[NH4Al(SO4)2]溶液中滴加足量Ba(OH)2溶液 NH4++Al...
-
有关叙述:能说明M比N的非金属*强的叙述是 ①非金属单质...
问题详情:有关叙述:能说明M比N的非金属*强的叙述是 ①非金属单质M能从N的化合物中置换出非金属单质N。 ②M原子比N原子容易得到电子。③单质M跟H2反应比N跟H2反应容易得多。 ④气态*化物水溶液的**H...
-
“吃得营养、吃出健康”是人们普遍的饮食追求,下列说法不正确的是A.人每天都应摄入一定量的蛋白质B.过量食用油脂...
问题详情:“吃得营养、吃出健康”是人们普遍的饮食追求,下列说法不正确的是A.人每天都应摄入一定量的蛋白质B.过量食用油脂能使人发胖,故应禁止摄入油脂C.糖类是人体能量的重要来源D.过量摄入微量元素不利于健康【回答】B知识点:各地中考题型:选择题...
-
一个质量为4kg的物体静止在足够大的光滑水平地面上.从t=0开始,物体受到一个大小和方向周期*变化的水平力F作...
问题详情:一个质量为4kg的物体静止在足够大的光滑水平地面上.从t=0开始,物体受到一个大小和方向周期*变化的水平力F作用,力F的变化规律如图所示.则( )A.t=2s时物体沿负方向运动的位移最大B.t=4s时物体运动的位移达最小值C.每个周期内物体的速度变化为一定值D.从t=0开...
相关文章
- Everybodylovesself-improvement.That’swhywe’resuchenthus...
- Recently,we’veoftenheardaboutearthquakesinsomeplacesint...
- YourNewYear’splantomovemoreisoneofthetoughesttostickto,...
- Youhaveputonfivekilogramsrecently.You’dbetter
- 句子改错。1.Thankyouverymuch.It’ssokindforyoutohelpus.2. Wha...
- Everwalkedtotheshopsonlytofind,oncethere,you’vecomplete...
- Youknowyouhavetoread“betweenthelines”togetthemostoutofa...
- Oneofthebestwaystochangeyourlooksandimproveyourhealthis...
- —WithyourhelpI’vecomefirst intheboy’s100meters.Thankyou...
- They’llsucceedinworkingouttheproblembecausetheynever