首页
登录
职称英语
Thousands of years ago man used handy rocks for his surgical operations. Lat
Thousands of years ago man used handy rocks for his surgical operations. Lat
游客
2025-04-20
19
管理
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. [br] 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://tihaiku.com/zcyy/4046384.html
相关试题推荐
Thousandsof______atthestadiumcametotheirfeettopaytributetoanoutstan
SeniorsandtheCityTensofthousandsofretiree
Thousandsofpeople______fromGreeceeveryyeartoworkinWestGermany.A、emig
Thousandsofyearsagomanusedhandyrocksforhissurgicaloperations.Lat
Thousandsofyearsagomanusedhandyrocksforhissurgicaloperations.Lat
Thousandsofyearsagomanusedhandyrocksforhissurgicaloperations.Lat
SpringtimedisplaysoffruitblossomsintheShenandoahValley______thousands
Hesayshehasn’tgotanymoney______infacthe’sgotthousandsofdollarsin.A、
LikethousandsofparentsacrossBritain,Ihavebeenscanningtheskieswit
LikethousandsofparentsacrossBritain,Ihavebeenscanningtheskieswit
随机试题
()现金支付()电汇[br]()面值()不可撤销信用证C、M
采用钢管作为灯具的吊管时,钢管内径一般不小于()mm。A.10 B.12
以下关于光纤特性的叙述中,不正确的是()。A.光纤传输信号传输损耗小 B.光
MAP红细胞保存液是在SAGM配方中加入了( )。A.代血浆 B.庆大霉素
IEEE制订了以太网的相关技术标准,其中1000Base-X(光纤吉比特以太网)
有一只怪钟,每昼夜设计成10小时,每小时100分钟,当这只怪钟显示5点时,实际上
项目管理中采用项目群管理方式的主要目的是为了()。A.更好地实现组织的战略目标
用来衡量企业所有者利用自有资金获得融资能力的比率是()。A.效率比率 B.杠
一般资料:男,29岁,海外归国留学生,公司技术主管。 求助问题:认为自己已感染
(2017年真题)对某产品进行价值分析,其产品功能与成本关系如下图所示,图中C1
最新回复
(
0
)