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
Thousands of years ago man used handy rocks for his surgical operations. Later he used sharp bone or horn, metal knives and, mor
Thousands of years ago man used handy rocks for his surgical operations. Later he used sharp bone or horn, metal knives and, mor
admin
2013-01-29
99
问题
Thousands of years ago man used handy rocks for his surgical operations. Later he used sharp bone or horn, metal knives and, more recently, rubber and plastic. And that was where we stuck, in surgical instrument terms, for many years. In the 1960s a new tool was developed, one which was, first of all, to be of great practical use to the armed forces and industry, but which was also, in time, to revolutionize the art and science of surgery.
The tool is the laser and it is, being used by more and more surgeons all over the world, for a very large number of different complaints. The word laser means: Light Amplification by Stimulated Emission of Radiation. As we all know, light is hot; any source of light--from the sun itself down to a humble match burning--will give warmth. But light is usually spread out over a wide area. The light in a laser beam, however, is concentrated. This means that a light with no more power than that produced by an ordinary electric light bulb becomes intensely strong as it is concentrated to a pinpoint-sized beam.
Experiments with these pinpoint beams have shown researchers that different energy sources produce beams that have a particular effect on certain living cells. It is possible for eye surgeons to operate on the back of the human eye without harming the front of the eye, simply by passing a laser beam right through the eyeball. No knives, no stitches, no unwanted damage--a true surgical wonder.
Operations which once left patients exhausted and in need of long periods of recovery time now leave them feeling relaxed and comfortable. So much more difficult operations can now be tried.
The rapid development of laser techniques in the past ten years has made it clear that the future is likely to be very exciting. Perhaps some cancers will be treated with laser in a way that makes surgery not only safer but more effective. Altogether, tomorrow may see more and more information coming to light on the diseases which can be treated medically.
The word "wonder" in line 17 is closest in meaning to ______.
选项
A、tragedy
B、influence
C、excitation
D、miracle
答案
D
解析
转载请注明原文地址:https://www.kaotiyun.com/show/HY1O777K
0
考博英语
相关试题推荐
Whatismeant【51】theword"friend"?Thedictionary【52】itas:."oneattachedto【53】byaffectionoresteem".Americansuset
Manytheoriesconcerningthecausesofjuveniledelinquency(crimescommittedbyyoungpeople)focuseitherontheindividualor
Watchababybetweensixandninemonthsold,andyouwillobservethebasicconceptsofgeometrybeinglearned.oncethebabyh
Watchababybetweensixandninemonthsold,andyouwillobservethebasicconceptsofgeometrybeinglearned.oncethebabyh
Amajorreasonforconflictintheanimalworldisterritory.Themaleanimalestablishesanarea.Thesizeoftheareaissuffi
AskanAmericanschoolchildwhatheorsheislearninginschoolthesedaysandyoumightevengetareply,providedyouaskit
Thisengineeringprojecthas______overallothersthisyear.
NewcomerstoSanFranciscowhocan’tspeakEnglishhaveahardtimefindinganapartment,ajob,orhealthcare.Institutionsth
Predictionsoflargepopulationsofrobotsinindustryhaveyettocometrue.Foradecadeormore,manufacturersofbigrobots
Mysisterisquite______andplanstogetaPh.Dinthefuture.
随机试题
109,某35岁孕妇,孕2产0,40周妊娠,自觉胎动减少1天来院就诊,行胎心监护OCT试验有频发晚期减速,24小时尿雌三醇小于10mg,则下一步处理是
我国会计制度规定,()采用多步式格式编制。
用于所获得或生产产品中的原产于东盟成员方的成分不少于该货物FOB价的(),并且最后的工序是在成员方境内完成,则认定原产国为东盟成员国。
从我国的实际情况来看,资产评估与审计的联系主要表现在()。
非现场检查主要是通过手工或计算机系统对上市公司上报的年度报告等资料进行定期和不定期的统计分析以及时发现存在的问题。()
治理通货膨胀的对策包括()。
自居易:在天愿作比翼鸟,在地愿为连理枝
有以下程序: main( ) { unsigned char a,b,c; a=0x3; b=a|0x8; c=b < < 1; printf("%d%d\n",b,c); } 程序运行后的输出结果是
A、WhenthePresidentandtheFirstLadydancedintheWhiteHouse.B、WhenanoldslavewasinterviewedaboutAmericanBlackHist
OfficialsattheWhiteHouseannouncedanewspacepolicyfocusedonmanagingtheincreasingnumberofsatellitesthatcompanies
最新回复
(
0
)