10．No one is glad to hear that his body has to be cut open by a surgeon（外科医生） and part of it is taken out．Today，however，we needn't worry about feeling pain during the operation．The sick person falls into a kind of sleep，and when he wakes，the operation is finished．But these happy conditions are fairly new．It is not many years since a man who had to have an operation felt all its pain．
Long ago，operations had usually to be done while the sick man could feel everything．The sick man had to be held down on a table by force while the doctors did their best for him．He could feel all the pain if his leg or arm was being cut off，and his fearful cries filled the room and the hearts of those who watched．
Soon after 1770，Josept Priestley discovered a gas which is now called"laughing gas"．Laughing gas became known in America．Young men and women went to parties to try 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 this gas．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．Wells felt no pain at all．As he didn't know enough about laughing gas，he gave a man less gas than he should 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 man died．Wells never forgot this terrible event．
21．It isB since a man being operated felt all the pain．
A．a few more years
B．not very long
C．few years
D．two thousand years
22．Long ago，when the sick man was operated on，heC．
A．could feel nothing
B．could not want anything
C．could feel all the pain
D．could do anything
23．Using the laughing gas，the people did not seem toB．
A．be afraid of anything
B．feel pain
C．want to go to the parties
D．be ill
24．If a man took less laughing gas than he should have when an operation went on，heC．
A．felt nothing
B．felt very comfortable
C．still felt pain
D．would die
25．One who took too much of the laughing gasB．
A．would laugh all the time
B．would die
C．would never feel again
D．would be very calm．
分析 文章大意：
文章那个主要介绍的是有关做手术是否麻醉的问题．很久之前，并没有麻醉剂可以使用，在手术过程中人们会很痛苦．后来一个人发现了笑气可以缓解手术过程中人们的疼痛感，但是用的太少的话没有效果，用得太多又会致死．
解答 21．B，细节理解题，文中提到"It is not many years since a man who had to have an operation felt all its pain"不久之前，人们在手术之前还会全程感受到疼痛，由此确定选择B．
22．C，细节理解题，文中提到"Long ago，operations had usually to be done while the sick man could feel everything"很久之前，人们在做手术的时候会感受到所有的疼痛，由此确定选择C．
23．B，细节理解题，文中提到"people didn't seem to feel pain when they were using this gas"当用笑气的时候，人们不会感受到疼痛，由此确定选择B．
24．C，细节理解题，文中提到"，he gave a man less gas than he should have．The man cried out with pain when his tooth was being pulled out"用少了笑气之后，在手术中途就会感觉到疼痛，由此确定选择C．
25．B，细节理解题，文中提到"his time he gave too much of the gas，and the man died"当笑气用多了的时候，人就会死亡，由此确定选择B．
点评 对于阅读表达题，一定要记得首先通读全文，了解文章大意，然后再根据文章关键词，关键句，掌握细节问题，并进行推理判断，再去回答具体的问题．
