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 mammals require sleep; it is an essential part of life. For giraffes, two hours a Line day is enough. For bats, that number
All mammals require sleep; it is an essential part of life. For giraffes, two hours a Line day is enough. For bats, that number
admin
2012-01-15
44
问题
All mammals require sleep; it is an essential part of life. For giraffes, two hours a
Line day is enough. For bats, that number is closer to twenty. The average adult human
needs between seven and nine hours of sleep every day. Despite these differences,
mammals all have one thing in common: If they do not get enough sleep, they can
(5) suffer serious mental and physical consequences.
The most extensive sleep research has been conducted on people. Through
these studies, scientists have identified two broad categories of sleep, which can
be further divided into five stages with distinct physiological functions. Taken
together, they form a complete sleep cycle. The first four stages are marked by a
(30) lack of rapid eye movement (REM). Therefore, they are referred to as non-REM
sleep. While people are engaged in non-REM sleep, several things are occurring.
Researchers have discovered that during this early sleep, the human body
releases a series of hormones responsible for the proper functioning of certain
body systems. Disrupted sleep can cause these hormones to fall out of balance.
(15) The results can contribute to disorders such as diabetes, depression, infertility,
or even cancer. Lack of sleep, especially in stages 3 and 4, can literally stunt the
growth of children and may increase rates of obesity in adults.
Stage 5 sleep is defined by the occurrence of rapid eye movement, otherwise
known as dreaming. Note that, while REM sleep is the final stage in a sleep cycle,
(20) a complete cycle generally lasts only about 95 minutes. A person will experience
four to six cycles in one sleep session, with REM sleep taking up a larger portion
of the cycle as the night continues. Scientists have advanced several theories
about why humans need REM sleep. One view is that dreaming aids in memory
consolidation. Under this theory, during REM sleep the brain not only strengthens
(25) memory of important actions or events, but it weakens memory of unimportant
things. Another view is that dreaming is necessary for proper central nervous
system development. Yet another theory suggests that REM sleep involves the
repair of monoamine receptors. The theories are not necessarily exclusive; in fact,
they all reach the conclusion that REM sleep deprivation can result in death.
The author of the passage is primarily concerned with
选项
A、promoting mammalian sleep research
B、documenting the importance of non-REM sleep in hormone regulation
C、describing the role of sleep in human behavior and development
D、arguing that humans need more sleep to function optimally
E、illustrating the importance of REM sleep to brain function
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/QtjO777K
本试题收录于:
GRE VERBAL题库GRE分类
0
GRE VERBAL
GRE
相关试题推荐
Thegrowthofachildisinfluencedbyanumberoffactors,______arebeyondourcontrol.
Newswritersareexpectedtobeclearandaccurate;theforminwhichtheywriteorspeakis______tothatrequirement.
Duringthelastthreedecadesthenumberofpeopleparticipatinginphysicalfitnessprograms______sharply.
Normallyastudentmustattendanumberofcoursesinordertograduate,andeachcoursewhichheattendsgiveshimagradewhic
Normallyastudentmustattendanumberofcoursesinordertograduate,andeachcoursewhichheattendsgiveshimagradewhic
Normallyastudentmustattendanumberofcoursesinordertograduate,andeachcoursewhichheattendsgiveshimagradewhic
Staffhavebeenholdinganumberof_________toraisemoneyforcharity.
Understandingthistransitionrequiresalookatthetwo-sidedconnectionbetweenenergyandhumanwell-being.Energycontribu
随机试题
对于二次补充侦查的案件,人民检察院仍然认为证据不足,不符合起诉条件的,如何处理?()
急性血源性骨髓炎的护理措施。
预真空压力蒸汽灭菌的监测有哪些基本要求?
女性患者最常见的霍奇金淋巴瘤组织学类型是
患者,女,45岁。反复对称性双手、双足关节肿痛10年,晨僵2~3小时,近1个月出现咳嗽、咳痰、有时喘憋、不发热。查体:双手轻度关节变形,双肺底可闻少许的细小湿性啰音。最可能的诊断是
男性,42岁,胃大部切除术(毕Ⅱ式):术后一年出现上腹部烧灼痛,进食后加重,抑酸剂治疗无效。治疗措施最合理的是
梅,高洁傲岸;兰,优雅空灵;竹,虚心有节;菊,冷艳清贞。千百年来,梅兰竹菊“四君子”以其清雅淡泊的品质,一直为古今文人墨客所钟爱。这表明()。①整体和部分是辩证统一的②共性寓于个性之中③对立和差别以同一为前提④不同事物有不同的矛盾
阅读下列材料,完成下列小题。大班科学活动:改装工具。准备:几大盆水;每个幼儿一箩筐材料:完好和有洞的桶、瓶、塑料袋;小箩筐、漏斗、漏网等:一组辅助材料:皮筋、橡皮泥、透明胶、塑料纸、剪刀、线等。活动开始,教师提出活动要求和注意
我国公务员的处分分为:警告、记过、记大过、降级、撤职五级。()
我国宪法规定的庇护权的含义是
最新回复
(
0
)