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
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
2014-12-31
60
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 laser beam, is powerful and can be made to do many things. The laser was first developed in 1960, about 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
细节题。文章最后一段第二句指出When something large is being built—for example,a large bridge一it is important to have very accurate measurements.即激光束在建造大型建筑物时发挥重要作用因为它可以精确测量。故选D。
转载请注明原文地址:https://kaotiyun.com/show/enq7777K
0
大学英语四级
相关试题推荐
Forthispart,youareallowed30minutestowriteashortessayentitledChangesinPeople’sDailyExpensesbasedonthestatis
There’snobetterfeelinginajobthanwhenyouknowthebosshasfullconfidenceinyou.Youenterazonewhereyoucanreally
There’snobetterfeelinginajobthanwhenyouknowthebosshasfullconfidenceinyou.Youenterazonewhereyoucanreally
There’snobetterfeelinginajobthanwhenyouknowthebosshasfullconfidenceinyou.Youenterazonewhereyoucanreally
ThefederalautomobileefficiencystandardsannouncedthisweekareanimportantsteponAmerica’spathtoalower-carbonandmo
ThefederalautomobileefficiencystandardsannouncedthisweekareanimportantsteponAmerica’spathtoalower-carbonandmo
ItisimpossibletomeasuretheimportanceofEdisonbyaddinguphisspecificinventions.Actually,hisnameis【B1】______withm
Whileit’seasyenoughtobrushoffafewsleeplessnightswithapotofcoffeeandtheoccasionaldesknap,youmaybedoingmo
Whileit’seasyenoughtobrushoffafewsleeplessnightswithapotofcoffeeandtheoccasionaldesknap,youmaybedoingmo
随机试题
宏观经济行政管理
不可气雾吸入给药的包括
患者男,45岁。因右侧下牙龈溃疡、疼痛3个半月人院。3个半月前发现原来右侧下牙龈上的黑斑逐渐长大,并出现溃疡,未诊治,近来溃疡范围加大,疼痛加重,易出血,体重下降6kg。全身检查:T37℃,P76次/分,R22次/分,BP130/87mmHg,身高1.70
下列属于建筑安装工程费用中人工费的是()。
袁某认为中川区房产管理局对他的房产信息记载有误,要求更正,该局拒绝。袁某向法院起诉该局不作为,请求法院判决该局在一定期限内更正,法院予以受理。该局认为,袁某的起诉超过法定期限。下列关于本案法院受理和举证责任的说法中,正确的有()。
下列关于职工薪酬的说法,正确的是()。
我国古代文学名作《桃花源记》的作者是()。
人类本质上的沉重感。主要源自于责任、期盼和压力。因而,承受便是生命的一种需要和方式了。我们不可能也决不能无任何负载地来往于世,作为人必须有所承受,承受我们需要承受的东西。在理想的王国里,我们承受亲人故人寄予的热望和要求;在生活路途上,我们承受着来自世俗的各
计算机网络最突出的优点是()。
Afteracarefulexamination,thedoctor______anewmedicalandatwo-dayrestforthepatient.
最新回复
(
0
)