Why we yawn 我们为什么打哈欠？

　　请注意，点开这篇文章可能会让你打哈欠！这并不是因为我们的节目太无聊或者你会被传染上哈欠，而是因为只要我们看到别人打哈欠，甚至只是想想这个行为，都可能引发我们来一个大哈欠！但这究竟是为什么呢，本集《随身英语》将会解答你的疑惑。

　　课文内容

　　Vocabulary:Biology词汇:生物学

　　It’s a question that has puzzled scientists for a long time:why exactly do we yawn?

　　In a recent breakthrough,scientists have discovered the part of the brain responsible for contagious yawning.It’s called the primary motor cortex,and controls movement in the body.When triggered it makes us yawn.But we can’t choose to yawn–it’s an involuntary imitation of other people.You know how it goes:your friend yawns,you yawn.

　　Knowing which section of the brain is involved is only part of the answer.There is still a deeper question of‘why’.And we don’t only yawn when others do,we sometimes yawn alone.

　　So,let’s start with the physiological theories behind yawning.As far back as 400BC,Greek physician Hippocrates speculated that yawning released harmful gases from the body,like“steam escaping from a cauldron”.His colourful theory is now,sadly,discounted.

　　A more recent idea suggests that we yawn in order to cool down the brain.Just like a busy computer processor,our brains can overheat.Psychologist Gordon Gallup from the University at Albany has argued that the act of yawning delivers a rush of oxygen to the brain,helping us think more clearly.

　　What about the connection between yawning and tiredness?We certainly yawn more when we’re feeling sleepy or sluggish,but why is this?Theories that it helps give the body extra energy are largely discredited,as we don’t yawn when we exercise,a time when we definitely need more get-up-and-go!

　　Psychologist Catriona Morrison from the University of Leeds says yawning is an ancient reflex.She told the BBC that it may have started in“the days of cavemen when someone had to be on watch all the time-yawning increases cerebral blood flow so can improve alertness.”

　　What about our friends'contagious yawning?Some think it comes down to empathy.While all vertebrate mammals yawn,only humans and chimpanzees‘catch’yawns from others.Studies have shown we yawn more frequently when in the company of close relatives and friends.Could yawning actually help us cement our closest relationships?

　　If it does,next time you yawn in company,don’t feel too embarrassed.You’re just showing off your people skills.

　　词汇表

　　contagious会传染的

　　motor肌肉运动的，运动神经的

　　cortex（尤指大脑或其他器官的）皮层

　　involuntary不由自主的

　　physiological生理的

　　physician医生（尤指内科医生）

　　cauldron（通常指架在火上的）大锅

　　colourful有趣的，有声有色的

　　discounted大打折扣的，有所减弱的

　　overheat负荷过多，承载过多

　　rush（身体的）一阵感觉

　　sluggish行动迟缓的

　　discredited受到怀疑的，被质疑的

　　get-up-and-go干劲

　　reflex本能反应

　　cerebral大脑的

　　come down to归结为，归根结底在于

　　empathy共鸣，共感

　　vertebrate有脊椎的

　　cement巩固（友谊）

　　people skills人际交往能力

　　测验与练习

　　1.阅读课文并回答问题。

　　1.Are we more likely to yawn in the company of our family or strangers?

　　2.Why don’t we think yawning gives you a rush of energy?

　　3.True or false:Humans and chimpanzees are the only mammals which yawn.

　　4.Which word means‘caused something to start’?

　　5.True or false:The author found Hippocrates’idea appealing.

　　2.请你在不参考课文的情况下完成下列练习。选择一个意思合适的单词填入句子的空格处。

　　1.Professor Li’s theory is ______.It is widely used in academia.

　　discredited discounted valid contagious

　　2.It really ______ to you.If you want something badly enough,you can make it happen.

　　Down come down downs comes down

　　3.A reflex is ______ action.

　　a voluntary an involuntary the voluntary a volunteer

　　4.Tim has great ______.He always knows how to get the best out of his team.

　　people skills empathy skills person skills cerebral skills

　　5.Wait until January to buy a new jacket and take advantage of the ______.

　　discounting discounted discounts discredit

　　答案

　　1.阅读课文并回答问题。

　　1.Are we more likely to yawn in the company of our family or strangers?

　　According to the article,we are more likely to yawn when with family and friends.

　　2.Why don’t we think yawning gives you a rush of energy?

　　The theory is no longer popular because if it were true,it would mean we would yawn at times when energy is badly needed,such as during exercise.

　　3.True or false:Humans and chimpanzees are the only mammals which yawn.

　　False.The article says all vertebrate mammals yawn,but it’s only contagious in humans and chimpanzees.

　　4.Which word means‘caused something to start’?

　　Triggered.

　　5.True or false:The author found Hippocrates’idea appealing.

　　True.The author seems to like Hippocrates’idea,calling it“colourful”and saying it was“sad”it was no longer accepted.

　　2.请你在不参考课文的情况下完成下列练习。选择一个意思合适的单词填入句子的空格处。

　　1.Professor Li’s theory is valid.It is widely used in academia.

　　2.It really comes down to you.If you want something badly enough,you can make it happen.

　　3.A reflex is an involuntary action.

　　4.Tim has great people skills.He always knows how to get the best out of his team.

　　5.Wait until January to buy a new jacket and take advantage of the discounts.