No one is glad to hear that his body has to be cut open by a surgeon and partof it taken out.Today,however,we needn’t worry about feeling pain during theoperation.The sick
person falls into a kind of sleep,and when he awakes,the operation isfinished.But these happy conditions are fairly new.It is not many years since aman who had to have
operation felt all in its pain.
Long ago,operation has usually to be done while the sick man could feeleverything.Sooner after 1770,Joseph Priestley discovered a gas which is nowcalled“laughing
gas”.Laughing as became known in America.Young men and women went to parties totry it.Most of them spent their time laughing,but one man at a party,Horace
Wells,noticed that people didn’t seem to feel pain when they were using thisgas.He decided to make an experiment on himself.He asked a friend to help him.
Wells took some of the gas,and his friend pulled out one of Well’s teeth.Wellsfelt no pain at all.
As he didn’t know enough about laughing gas,he gave a man less gas than heshould have.The man cried out with pain when his tooth was being pulled out.
Wells tried again,but this time he gave too much of the gas,and the mandied.Wells never forgot this terrible event.
没有人愿意听见自己的身体被外科医生割开并切除某些部分。但是现在，我们在做手术期间不用担心感到疼痛。病人陷入睡眠中，当他醒来时手术已经结束
了。但是这种令人愉悦的方式是相当新奇的。就在不久前一个人在做手术时还会觉得疼。
很久以前，手术都是在病人完全清醒的时候做的。在1770过后不久，约瑟夫.普利斯特发现了一种气体现在被称作“令人笑的气”。笑气被美国人知道了。年轻
人们都去舞会上体验这种气体。他们大部分人都哈哈大笑，但是一次一个宴会上的人，霍尔斯.威尔士发现当人们使用这种气体的时候就不会感觉到疼痛。他决
定在自己身上做个试验。他邀请了一位朋友帮他。
威尔士取出一些气体，然后他的朋友拔出他的一颗牙。威尔士一点也没有感觉到痛。
因为他对笑气了解不多，他在另一个人身上试验时，用的笑气的量小于应用的量，所以当这个人的牙齿被拔出时，他痛苦的大喊大叫。
威尔士又试了一次，但是这次他用的笑气的量太多，导致这个人死了威尔士永远也忘不了这个可怕的经历。
 It is no long since a man felt all the pain while being operated.就在不久前一个人在做手术时还会感觉到疼。
A：T B：F
 2.Long ago,when the sick man was operated on,he could feel nothing.很久以前，当病人做手术时，他就没什么感觉。
A：T B：F
 3.Using the laughing gas,the people seemed to feel pain during the operation.使用笑气之后，人们在做手术期间好像能感觉到疼痛。
A：T B：F
 4.If a man took less laughing gas than he should have when an operation wenton,he still felt pain.如果一个人使用的笑气少于应用的量，那么在手术进行期间他仍然能
感觉到疼。
A：T B：F
 5.One who took too much of the laughing gas would die.服用过量的笑气会导致人死亡。
A：T B：F