海豚是如何睡觉的?
文章来源:未知 文章作者:enread 发布时间:2020-03-26 08:46 字体: [ ]  进入论坛
(单词翻译:双击或拖选)

海豚在很多方面都和人类很像。比如说海豚有和人类很像的特殊的呼吸系统,唯一的不同是海豚能不呼吸氧气在水下呆很长时间。但是海豚使如何做到睡觉不溺水呢?
Since Dolphins are like human being in so many ways. For example, dolphins have a special respiratory system  just like humans. The only difference is that dolphins are able to stay underwater for a long time without breathing oxygen. But how do dolphins manage to sleep without drowning?
 
Generally, dolphins sleep with only one brain hemisphere in slow-wave sleep at a time, thus maintaining enough consciousness to breathe and to watch for possible predators1 and other threats. Earlier sleep stages can occur simultaneously2 in both hemispheres. In captivity3, dolphins seemingly enter a fully4 asleep state where both eyes are closed and there is no response to mild external stimuli5. In this case, respiration6 is automatic; a tail kick reflex keeps the blowhole above the water if necessary. Anesthetized dolphins initially7 show a tail kick reflex. Though a similar state has been observed with wild sperm8 whales, it is not known if dolphins in the wild reach this state. The Indus river dolphin has a sleep method that is different from that of other dolphin species. Living in water with strong currents and potentially dangerous floating debris9, it must swim continuously to avoid injury. As a result, this species sleeps in very short bursts which last between 4 and 60 seconds.


点击收听单词发音收听单词发音  

1 predators 48b965855934a5395e409c1112d94f63     
n.食肉动物( predator的名词复数 );奴役他人者(尤指在财务或性关系方面)
参考例句:
  • birds and their earthbound predators 鸟和地面上捕食它们的动物
  • The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》
2 simultaneously 4iBz1o     
adv.同时发生地,同时进行地
参考例句:
  • The radar beam can track a number of targets almost simultaneously.雷达波几乎可以同时追着多个目标。
  • The Windows allow a computer user to execute multiple programs simultaneously.Windows允许计算机用户同时运行多个程序。
3 captivity qrJzv     
n.囚禁;被俘;束缚
参考例句:
  • A zoo is a place where live animals are kept in captivity for the public to see.动物园是圈养动物以供公众观看的场所。
  • He was held in captivity for three years.他被囚禁叁年。
4 fully Gfuzd     
adv.完全地,全部地,彻底地;充分地
参考例句:
  • The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气,然后全部呼出。
  • They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。
5 stimuli luBwM     
n.刺激(物)
参考例句:
  • It is necessary to curtail or alter normally coexisting stimuli.必需消除或改变正常时并存的刺激。
  • My sweat glands also respond to emotional stimuli.我的汗腺对情绪刺激也能产生反应。
6 respiration us7yt     
n.呼吸作用;一次呼吸;植物光合作用
参考例句:
  • They tried artificial respiration but it was of no avail.他们试做人工呼吸,可是无效。
  • They made frequent checks on his respiration,pulse and blood.他们经常检查他的呼吸、脉搏和血液。
7 initially 273xZ     
adv.最初,开始
参考例句:
  • The ban was initially opposed by the US.这一禁令首先遭到美国的反对。
  • Feathers initially developed from insect scales.羽毛最初由昆虫的翅瓣演化而来。
8 sperm jFOzO     
n.精子,精液
参考例句:
  • Only one sperm fertilises an egg.只有一个精子使卵子受精。
  • In human reproduction,one female egg is usually fertilized by one sperm.在人体生殖过程中,一个精子使一个卵子受精。
9 debris debris     
n.瓦砾堆,废墟,碎片
参考例句:
  • After the bombing there was a lot of debris everywhere.轰炸之后到处瓦砾成堆。
  • Bacteria sticks to food debris in the teeth,causing decay.细菌附着在牙缝中的食物残渣上,导致蛀牙。
上一篇:糖与记忆的关系 下一篇:没有了
TAG标签: 英语科普 睡觉 海豚
发表评论
请自觉遵守互联网相关的政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
验证码:点击我更换图片
梧州患该化妆品有限公司