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
专升本
A very interesting and important development in science is a device called laser. A laser is a machine which produces a light be
A very interesting and important development in science is a device called laser. A laser is a machine which produces a light be
admin
2019-03-28
43
问题
A very interesting and important development in science is a device called laser. A laser is a machine which produces a light beam. The light produced by a laser is a very special kind of light. The light, called a laser beam, is powerful and can be made to do many things. The laser was first developed in 1960, about more than half a century ago.
There are many different uses for lasers and several different types have been developed. Some use gases to produce the light beam. The gases are heated and cooled, and these processes cause the gases to produce energy in the form of light. One special point of lasers is that the light beam can be stored. If the stored light is then suddenly let go, it is extremely powerful. The light from a laser beam can be used either by storing it and letting it go suddenly, or by using it in a continuous stream.
There are three important areas where the control of the laser beam has been put into use by scientists. These areas are industry, communications, and medicine. In each area, the scientists have been able to use the laser to do things that they could not do in another way. The laser has been very helpful.
In industry, the laser beam has been used for measurement and drilling. When something large is being built—for example, a large bridge—it is important to have very accurate measurements. By accurate measurement, lasers are also helpful in laying down pipelines over long distances. As lasers become more common in industry, there will be more and more uses for them.
What is important in building large things?
选项
A、To drill holes accurately.
B、To lay down long pipelines.
C、To cut pipes by lasers.
D、To measure accurately.
答案
D
解析
根据最后一段第二句“When something large is being built—for example,a large bridge—it is important to have very accurate measurements.”可知,在建造大型建筑物时,精确的测量很重要。故选D。
转载请注明原文地址:https://kaotiyun.com/show/NBJC777K
本试题收录于:
英语题库普高专升本分类
0
英语
普高专升本
相关试题推荐
()himdothisjobbyhimself?
Withthedevelopmentofindustry,thisregionwillsurely().
A、Itisharmfultoheartsurgerypatientswithstomachbleeding.B、Itshouldnotbetakenbyheartsurgerypatientsbeforetheo
Mostdoctorsrecognizethatmedicineisasmuchanartasitisascience.
Mostofthestudentsaresaidto______theproposednewtrainingsystem.
Inmostcultures,whenyoumeetacquaintancesforthefirsttimeduringaday,itisnormaltogreetthem.Themainpurposeoft
OneBritishschoolisfindingthatallowingchildrentolistentomusicoreventohavetheTVonwhilestudyingishelpingimpr
Subwaysareundergroundtrains,whichusuallyoperate24hoursaday.Theyarefoundinlargercitiesandusuallyrunbetweenth
Thegoods_______whenwearrivedattheairport.
随机试题
哪些区域和场所严禁动火?
决策目标的确定需要符合的要求有()
A.5~2.0cm2B.≤2.0cm2C.≤1.5cm2D.≤1.0cm2E.2.0~2.5cm2出现跨瓣压差时二尖瓣狭窄面积在
水泥混凝土路面采用的集料中有害杂质主要指()的含量。
企业资产评估的基本方法有()。
水电建设工程施工必须坚持的方针是()。
供热管道连接,一般采用()方式。
动态主机设置协议(DHCP)是一个局域网的网络协议,它使用UDP协议工作,下列有关DHCP用途的说法中,不正确的是()。
美元指数是综合反映美元在国际外汇市场汇率情况的指标,用来衡量美元兑一揽子货币的汇率变化程度。据此判断美元指数是()。
You’rebusyfillingouttheapplicationformforapositionyoureallyneed;let’sassumeyouonceactuallycompletedacoupleo
最新回复
(
0
)