首页
登录
职称英语
All animals must rest, but do they really sleep as we know it? The answer to
All animals must rest, but do they really sleep as we know it? The answer to
游客
2025-04-26
51
管理
问题
All animals must rest, but do they really sleep as we know it? The answer to this question seems obvious. If an animal regularly stops its activities and stays quiet and unmoving - if it looks as though it is sleeping - then why not simply assume that it is in fact sleeping? But how can observers be sure that an animal is sleeping?
They can watch the animal and notice whether its eyes are open or closed, whether it is active or lying quietly, and whether it responds to light or sound. These factors are important clues, but they often are not enough. Horses and cows, for example, rarely close their eyes, and fish and snakes cannot close them. Yet this does not necessarily mean that they do not sleep. Have you ever seen a cat dozing with an eye partly open? Even humans have occasionally been observed to sleep with one or both eyes partially open. Animals do not necessarily lie down to sleep either. Elephants, for example, often sleep standing up, with their tusks resting in the fork of a tree. Finally, while "sleeping" animals often seem unaware of changes in the sounds and light and other stimuli around them, that does not really prove they are sleeping either.
Observations of animal behavior alone cannot fully answer the question of whether or not animals sleep. The answers come from doing experiments in "sleep laboratories" using a machine called the electroencephalograph (EEC). The machine is connected to animals and measures their brain signals, breathing, heartbeat, and muscle activity. The measurements are different when the animals appear to be sleeping than when they appear to be awake. Using the EEC, scientists have confirmed that all birds and mammals studied in laboratories do sleep. There is some evidence that reptiles, such as snakes and turtles, do not truly sleep, although they do have periods of rest each day, in which they are quiet and unmoving. They also have discovered that some animals, like chimpanzees, cats, and moles (who live underground), are good sleepers while others, like sheep, goats, and donkeys, are poor sleepers. Interestingly, the good sleepers are nearly all hunters with resting places that are safe from their enemies. Nearly all the poor sleepers are animals hunted by other animals: they must always be watching for enemies, even when they are resting. [br] According to the author, all animals ______.
选项
A、spend some time resting
B、close their eyes when sleeping
C、are good sleepers
D、are poor sleepers
答案
A
解析
转载请注明原文地址:https://tihaiku.com/zcyy/4053943.html
相关试题推荐
Allanimalsmustrest,butdotheyreallysleepasweknowit?Theanswerto
Allanimalsmustrest,butdotheyreallysleepasweknowit?Theanswerto
Allanimalsmustrest,butdotheyreallysleepasweknowit?Theanswerto
Allanimalsmustrest,butdotheyreallysleepasweknowit?Theanswerto
Itwas(andis)commontothinkthatotheranimalsareruledby"instinct"wh
Itwas(andis)commontothinkthatotheranimalsareruledby"instinct"wh
Itwas(andis)commontothinkthatotheranimalsareruledby"instinct"wh
Youreallyoughtto______;alltheselatenightsaredoingyounogood.A、bring
Whydoesstorytellingendureacrosstimeandcultures?Perhapstheanswerli
Whydoesstorytellingendureacrosstimeandcultures?Perhapstheanswerli
随机试题
Thefacesofelderly,happily-marriedpeoplesometimesresembleeachother.
Inthepopularmind,theInternetistherealizationoftheglobalvillage,
BabyBodyLanguageI.Fistinmouth—Indicationa)Hungry:ruledoutifthebaby
PaparazziTheterm"paparazzi"comesfroma
甲公司为一家拟上市的医药生产公司,该公司董事会目前正在审查公司的内部控制系统。
清河二中的张校长说高三学生从前的那种勤奋学习的精神越来越不多见了,因为我发现目前
破产企业按照经批准的职工安置方案支付所欠职工的工资,将相关账面价值与实际支付的金
健康观的三个维度包括() A.身体、心理和团体 B.身体、心理
关于胃大部切除术后十二指肠残端破裂的叙述,下列哪项不正确? A.大部分病
对混凝土有快硬高强要求的条件下不宜使用()。A.硅酸盐水泥 B.普通硅酸盐水泥
最新回复
(
0
)