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
78
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://www.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
Young()shewas,shewasequal,tothetask.
A:听起来不错。有机会我一定去北京玩玩。
ForanyEnglishman,therecanneverbeanydiscussionastowhoistheworld’sgreatestpoetandgreatestdramatist.Onlyonena
Laptopsarenowsoexpensive______beyondthereachofalmosteveryone.
A、Itallowshimtomakealotoffriends.B、Itrequireshimtoworklonghours.C、Ithelpshimunderstandpeoplebetter.D、Iten
Thehumanbraincontains10thousandmillioncellsandeachofthesemayhaveathousandconnections.Suchenormousnumbersused
A、Theartofsayingthankyou.B、Thesecretofstayingpretty.C、Theimportanceofgoodmanners.D、Thedifferencebetweenelegan
A、Reviewthedetailsofallherlessons.B、Comparenoteswithhisclassmates.C、Talkwithherabouthislearningproblems.D、Foc
Inmostcultures,whenyoumeetacquaintancesforthefirsttimeduringaday,itisnormaltogreetthem.Themainpurposeoft
Smokingisnotgood______youbecauseitcanaffectyourhealth.
随机试题
阐述静态库和动态库的概念,论述它们各自的优缺点。
青春期常见的心理行为问题是
可抑制反转录酶活性的一组药物是
瘀血疼痛的特点有
下列哪些行为构成走私犯罪的共犯?()
市场交易数量与交易行为产生的市场冲击成本成正比。()
下列各项中,属于法律事实中人的行为范围的是()。
“能感受到家乡的发展变化并为此感到高兴”该社会领域目标的典型表现所属的年龄段是()
设f(x)=φ(a+bx)一φ(a一bx),其中φ(x)在(-∞,+∞)内有定义,且在点a处可导,求f′(0).
WhydoweneedtheEnglishmajor?The【C1】______isineverymouth—or,atleast,isdiscussedextensivelyincolumnsand【C2】______
最新回复
(
0
)