首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
All animals must rest, but do they really sleep as we know it? The answer to this question seems obvious, If an animal regularl
All animals must rest, but do they really sleep as we know it? The answer to this question seems obvious, If an animal regularl
admin
2013-01-15
39
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.
How can researchers in "sleep laboratories" tell that the animals they are observing are asleep or not?
选项
A、They see if the animals respond to light and sound.
B、They do this by observing changes in the animals’ brain signals, breathing, heartbeat, and muscle activity.
C、They see if the animals’ eyes are closed.
D、They can tell this by seeing if the animals lie down or not.
答案
B
解析
从第三段“The answers come from…than when they appear to be awake.”可知,研究人员用一种叫做EEC的机器测量脑信号、呼吸、心跳和肌肉活动,以判断它们是否在睡觉,因为动物睡觉时和醒着时,测量结果是不一样的。
转载请注明原文地址:https://jikaoti.com/ti/ub8YFFFM
0
考博英语
相关试题推荐
Exactlywherewewillstandinthelongwaragainstdiseasebytheyear2050isimpossibletosay.(111)Butifdevelopmentsin
Itisnottoolate,but______actionisneeded.
Failuretoadvertise(could)resultineither(reduced)salesand(less)profit(nor)legalactions.
Thinkaboutwhatwouldmakeyoureally,reallyhappy.Moremoney?Wrong.Smiling,well-adjustedkids?Wrongagain.Thefactisw
Ifthereisonethingscientistshavetohear,itisthatthegameisover.Raisedonthebeliefofanendlessvoyageofdiscove
Thisbookisabouthowthesebasicbeliefsandvaluesaffectimportant______ofAmericanlife.
Thechild’searliestwordsdealwithconcreteobjectsandactions,itismuchlaterthatheisabletograsp______.
Theworld’seconomywillgrowstronglythisyearandnext,buildingontherecoverythatstartedinthesecondhalfof2003.Tha
Listeningoutforwhalesongisonewaythatshipscanavoidcollidingwithwhales.Butwhatdoyoudoifthewhalesaren’tsing
Listeningoutforwhalesongisonewaythatshipscanavoidcollidingwithwhales.Butwhatdoyoudoifthewhalesaren’tsing
随机试题
他的家庭很贫穷,经常穿一些过时的衣服。
治疗慢惊风脾肾阳衰证首选方是()
某公司是一家大型的跨国公司,长期以来,公司高层在纳才、用才方面均采用了科学的管理方法。其人力资源部一贯坚持“考绩定人事”的原则(他们把员工分为优秀、合格、试用三种,分别享受不同的待遇。公司规定每季度进行一次业绩考评,并根据考评结果使员工晋升到不同的等级)。
我国《旅游法》第10条规定,旅游者的()应当得到尊重。
下列关于班轮航线参数的说法正确的是()。
—It’s$500,butthatismylastoffer.—OK,itisa______.
感情放养,是指婚姻中彼此间的相互信任和相互尊重,给对方适度的自由空间,从而达到双方和谐相处的关系状态。根据上述定义,下列属于感情放养的是()。
[2008年1月]a=一4。(1)点A(1,0)关于直线x—y+1=0的对称点是A’();(2)直线l1:(2+a)x+5y=1与直线l2:ax+(2+a)y=2垂直。
中国共产党在长征途中召开的遵义会议上集中解决的主要问题是()。
信息系统安全体系应当由________共同构成。
最新回复
(
0
)